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CPIG’S HPTuners VEHICLE TUNING
GUIDE
Version 16JUL07
I created this guide to give myself a step by step method that I could follow while tuning my car. I read for
months through the forums and manuals but never really found what I was looking for – an up to date, easy
to follow, start to finish guide that someone new to tuning could use to completely tune his car. (I don’t know
how long this guide will be up to date but hopefully it will be useful for a little while).
I borrowed most of the content for this guide from many different people and sources. Thank you to all of
these people for their hard work – I had the easy part, just cut and paste. (Big thanks to Bill@hptuners and
Eagle for their work).
If you see anything you don’t like or you have suggestions, I’m always open to change, just PM or email me
through the HPTuners forum.
There are two tuning methods discussed in this guide. Narrowband and Wideband Methods (NB and WB).
The NB method utilizes your LTFTs and STFTs to tune the VE table. It is a NB method because your PCM
gets input from your NB O2 sensors to calculate STFTs and LTFTs. This method is not accurate for tuning in
Power Enrichment (PE) and/or WOT because the NB sensors are not very accurate outside of 14.7:1 AFR.
To accurately tune for WOT or PE, you must use a Wideband O2 sensor.
The Wideband method is the best method to use but it will cost you a little extra. You will have to purchase a
WB O2 sensor such as the LC-1. You will also have to have the VCM Pro version of HPTuners, although
there are methods to connect the input from the WB to your EGR or A/C sensor wiring.
If you are not thoroughly familiar with the workings of an EFI engine I suggest you read “Fundamentals of
GM OBDII EFI Engines” in the EFI Live Scanner Manual. The manual is a free download at the EFI Live
site.
Another good reference is Bill@HPTuners’ quickstart guides which can be found here:
http://www.hptuners.com/forum/showthread.php?t=5691
1
STEP 1
PRE TUNE CHECKS
(Thanks to Eagle and ?)
Before starting, make sure you have a saved copy of your original tune.
Also, make sure your IFR/Injector Flow Rate table is set BEFORE attempting VE tuning.
I use the stock values for my Z06 because I still have the stock injectors.
If you don’t know your stock values, or you have changed injectors, you can let
HPTuners Editor help figure these values out for you. (You will need to know your fuel
pressure at the rail for this method):

Engine>Fuel Control>General Tab>Injector Control>Flow Rate vs. KPA

Open up the Unit Conversion window found under the Tools menu.
2

In the lower right, enter in your new injector flow rating and the fuel pressure it is
rated at.

Then enter in the fuel pressure of your fuel rail.

Your new injector flow rate will be calculated automatically. This rating is for 0
VAC.

As manifold vacuum increases the injector flow rate will slightly increase
Now start the car and verify with Scanner that everything is working properly.
 Start it and begin scanning and/or logging (Use scanner default PIDs under the
Table portion). Keep the PID file under 24 bytes to keep optimal FPS.
 First verify everything seems mechanically sound (oil pressure, etc.).
 Next, look at the MAF flow and/or frequency. As you blip the throttle this value
should increase/change.
 Let the car run for a while to heat up and go through its DTC tests. Watch out for
any kind of SES light. If any are observed determine if it is a
mechanical/electrical problem or if it is simply caused by a new engine
combination (camshaft, etc.).
 Once the vehicle is up to operating temperature verify that the O2 sensors are
responding to changes in the throttle.
 If the vehicle seems to be running decently (no pinging or potentially problematic
situations) drive it around for a while. Monitor the STFTs, LTFTs, and O2 values
and ensure no great splits exist, exhaust leaks, etc. If the O2 sensors are old or just
aren't switching fast enough (anti-freeze and RTV can both kill them easily) they
should be replaced before continuing any further.
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STEP 2
TUNING THE VE TABLES USING LTFTs and STFTS
Narrowband Method (Skip to Alt Step 2 for Wideband users)
(Thanks to Eagle and ?)
SIMULATE A MAF FAILURE:
When the MAF fails, the PCM falls into SD mode, where instead of using the measured
air mass provided by the MAF, it uses a calculated air mass value derived from the VE
table. This enables us to tune our VE table without interference from the MAF. The PCM
will also default to the Low Octane Spark Table as an added safety measure. To simulate
this MAF failure, we will do the following:

In the VCM Editor go to Engine Diagnostics>Airflow>MAF Fail High = 0 (stock
setting is 13500 MHz). This will set a P0103 code and turn on the SES light.
Ensure that the P0103 DTC is enabled and you are seeing P0103 in the DTC list.
Do not disable this code as you will not go into SD with it disabled. Just ignore it
or set the DTCs to no MIL light.
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
Then go to Engine>Spark Control>Spark Advance>Main Spark Advance. Copy
the High Octane table to the Low Octane table. The computer reverts to the low
octane table when a MAF failure is indicated, this will assure optimal timing.

Flash the PCM (calibration flash)

Optionally, some choose to unplug their MAF here to ensure it is not in play
during SD mode tuning. NOTE: MAFs that have the intake air temp (IAT) built
into them cannot be unplugged.
RESET FUEL TRIMS:
 Start the VCM scanner Histogram display. File>Connect. Then on the Toolbar go
to VCM Controls>Fuel & Spark>Fuel Trim Learn>Reset Fuel Trims.
ALLOW PCM TO LEARN LTFTs:
 Drive around until the LTFTs mostly learn themselves out. (About 1 hour or 100
miles). This is a guideline more than anything else, because the longer the engine
falls into a particular MAP vs. RPM cell, the quicker the corresponding LTFT
will be learned. In an idle or cruise cell, for example, it will be learned very
quickly. The standard we will use to determine whether or not the LTFTs are
learned is the STFTs. When your STFTs are all fairly near 0, your LTFTs will be
learned. You can do this driving all at once, or over a few days or a week. Make
an effort as you drive to hit various RPMs and MAP values as you can, as often as
you can. Your driving style should be calm with no sudden throttle inputs. It’ll
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
help if you have the scanner operating as you drive, so you can visually see which
cells you are falling into on you LTFT histogram.
Alternatively you can eliminate the driving around (learning LTFTs) step by
turning off LTFTs under Engine>Fuel Control>OL & CL>LTFT disabled, and
immediately start tuning with the STFTs as soon as the oil temperature is up to
normal values. Oil temperature is used as the guide, since it takes longer for the
block to reach its operating temperature from a cold start. You can substitute
STFTs for LTFTs and skip to STEP 2.1 “Tuning With STFTs Alone”.
LOG:
If you haven’t done so already, you should now get your scanning/logging software
hooked up and ready to go. HPTuners default PID logging settings are sufficient. The
suggested minimum parameters to be logged are:
 RPM
 MAF flow (g/sec or lb/min)
 MAF Frequency
 MAP
 Spark Advance / Ignition Timing Advance
 Knock Retard
 Injector Pulse width (Bank 1 and 2)
 O2 sensors - B1S1 and B2S1
 IAT
 IAC
 LTFT (Bank 1 and 2)
 STFT (Bank 1 and 2)
When you are ready to log (after your LTFTs have been learned), start by bringing the
car up to operating temp.
Begin logging, and again try to hit as many cells on your histogram as possible. A 20
minute or so logging session should be sufficient.
STOP LOGGING AND SAVE:
 Do NOT turn off the engine until the log is saved or it will be lost. (Note: If all the
LTFTs in your histogram are between +/- 10, skip ahead to “Tuning with STFTs
Alone”)
COPY LTFT HISTOGRAM INTO VE TABLE:
 Go to VCM Scanner>Histogram display>LTFTs.
 Open the VCM Editor>Edit>Engine>Airflow>Main VE and select Primary VE
vs. RPM vs. MAP.
 Now, copy your LTFT histogram, and “Paste Special – Add” it into the VE table.
 Do the same with your STFT histogram.
SMOOTH VE TABLE:
 After adding these values in, take a look at the 3-D graph of the VE table. You
may have large depressions or spikes corresponding to cells that you didn’t have
logged LTFT data for. Individually smooth these using the 3-D graph. Just click
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on the peak or valley and move it up or down so that it conforms to the rest of the
graph.
SAVE AND FLASH PCM:
 When this is done, save the .bin file and flash the PCM with it.
REPEAT:
 Repeat the LTFT learning process again, and then make another log. What we are
looking for now are LTFTs between +/- 10. If the preceding steps were followed
correctly, they all should be. However, it may be necessary to repeat the (LTFT +
STFT) + VE procedures again before your LTFTs fall in line. When they do, we
can move on to “Tuning With STFTs Alone”.
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STEP 2.1
TUNING WITH STFTS ALONE
Narrowband Method (skip to Alt Step 2 for wideband users)
Now things get quite a bit easier, because we no longer have to wait for LTFTs to be
learned.
 First off, set LTFT to disabled - Engine>Fuel Control>OL & CL>LTFT disabled.
 Then go to Engine>Fuel Control>Power Enrich. Look for the MAP field under
the “PE Enable” heading, and set it to 640 (This will disable PE mode. We don’t
want it interfering with our next step).
 Save these parameters and load it onto your PCM. Now we get to do some more
logging.
Method here becomes very important. We want to start out by getting the vehicle up to
operating temp, like always. Try to find a long stretch of road with no stops. A high speed
limit here also helps.
 Start the STFT histogram as you’ll be referencing it quite a lot while you’re
driving, and start logging.
 Get into third gear for an M6, (if you have an A4 you may have to experiment to
find a gear that works well for the following procedure), and level the RPMs off
at about 1200.
 Now, we’re going to “pulse” the gas pedal, constantly going from 0 – 100% TPS
(this is why we disable PE mode) at a steady rate. This can be a bit tricky, but the
object is to hit every MAP cell for the 1200 RPM column from off-idle to WOT.
You should be able to cycle through the column a couple times before the engine
falls into the 1600 RPM column.
 Continue doing this for all subsequent RPM columns.
 As an alternative, you can find a road with rolling hills, choose the appropriate
gear, set the cruise control at 1200, 1600, etc., and the change in load will cause
the MAP to climb in each rpm row.
 If you plan on using your MAF again after tuning your VE table, you can stop if
you want at the 4000 RPM column. If you plan on going straight SD, keep on
truckin! The higher the RPMs get, the tougher it’s going to be to get all the cells
in the column. Its okay if you miss a few (even a bunch) because we can always
hand smooth later. Also, the most important cells to hit in these higher RPMs are
going to be the WOT ones. The more correct we can get them, the easier it is
going to be to tune the PE table (if going SD), so try to hit them all if you can. If
you are good, you can hit all these cells often enough to get a good average STFT.
You can tell that you’ve found the average STFT for a cell (or close to it) when
you “pulse” through it and the STFT value doesn’t change anymore. Just keep at
it until you get a good average of as many cells as you can.
 Now, save the log.
 Like before, we are going to take our STFT histogram and “Paste Special – Add”
it into the VE table.
 Save the table and flash the PCM
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


Do another logging run using the same procedures as in the previous paragraph.
Now your STFTs should be very close to zero, if they are, this time we’re going
to “Paste Special – Multiply by % - Half” the STFT histogram into the VE table.
Individually smooth any large spikes or dips.
Save the table and flash the PCM.
Now we can log again just to verify where we’re at. If you are happy with your STFTs
(they should all be within a couple points of 0 now) down low, you can skip spinning up
to the high RPMs if you want. You could also keep logging and applying your STFTs
into the VE table as many times as you want, but you probably won’t be able to improve
your VE table very much more (assuming your STFTs are very close to 0. If not, wash,
rinse and repeat.).
Now we get to spend some quality time with the 3-D graph of the VE table. At this point,
there should not be any big peaks or valleys.
 Hand smooth only for cells in which you didn’t log any data, so that they
correspond with the logged cells around them. Personally, I don’t use polynomial
smoothing at all. It modifies the VE values enough so that it throws my STFTs off
significantly. That and my VE table is pretty smooth already between the
application of my STFTs and hand smoothing. Generally, it’s okay if the VE table
is a little choppy, and long as it doesn’t look like the Rockies and you aren’t
experiencing any burst knock.
Now that your VE table is so pretty and correct, go back and re-enable PE mode by:
 Setting the PE Enable MAP value back to 15.
 Switching LTFT Enable back to “ON”.
 Flashing your PCM.
Drive around for a few days or a week, and re-log to see where your LTFTs ended up.
They should all now be within the 0 and - 5 standard.
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ALTERNATE STEP 2
(For VCM Pro users with Wideband)
SPEED DENSITY TUNING USING WIDEBAND O2 INPUT
(Thanks to foff667/Bill@HPtuners - taken from HPT help file)
For me, this method is the best to use as it covers tuning of your VE tables, WOT/PE, and
MAF sensor. It utilizes AFR Error % and MAF–AFR Error histograms to correct your
VE and MAF tables. AFR Error is basically the difference between Actual AFR (as read
by your WB) and Commanded AFR (values that you have put into the PCM).
This portion of the Guide was written by foff667 for the HPTuners manual. I basically
just cut and pasted from the manual into this guide and added a couple suggestions.
Setting up your scanner:
 Open the HPT Scanner.
 Open the Table portion to set up your PIDs
 The default config is a good starting point, from there just add:
Wideband Input ie LM1, LC1, PLX, etc…
Air Fuel Ratio Commanded Hi Resolution
NOTE: Just keep in mind that the more PIDs you have the less frames per second of
data it will gather so make sure you keep it under 24 bytes.

Save the PID file as SD tuning.cfg by clicking on the Save Config file button
It should look something like this
10
Set up Open Loop Speed Density:
 Read your PCM & Save as stock.hpt
 Open the saved file with the editor
 Open both Primary & Secondary VE Tables if applicable and multiply these
tables by 1.15…this is just to add extra fuel in so you run safer while in SD mode.
It should look something like this (your numbers will be different):
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Under Fuel Cutoff/DFCO set DFCO enable normal to 284°F; this is so deceleration
fueling won’t affect the tuning process. Under normal conditions the computer leans out
the a/f mixture when you let off the gas which can skew the numbers you gather for
tuning your VE table.
It should look like this:
Under Power Enrichment set the EQ ratio vs. RPM to your desired a/f across the board.
This will make for one less step once you go back into closed loop.
(Cpig edit: For my LS6 / Z06 I use 1.13 up to 4000 rpm, 1.167 through 6000rpm then
1.15 to the rev limiter. This gives me 13:1 AFR up to my Peak Torque band where I
richen to 12.6:1 AFR through my Peak Torque Band then lean slightly to 12.8:1 AFR for
my Peak Horsepower Band. You have to find what works best for your engine though).
It should look somewhat like this:
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Under Fuel Control-Open & Closed loop open “Open Loop EQ Ratio” and set it to 1.00
all the way across. This will set all cells to a 14.7:1 air fuel ratio.
Like this
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Next set Long Term Fuel Trims to Disabled
Like this:
Then set All Closed Loop Enable Temp cells to 284°F this will ensure you go into open
loop.
Like this:
Under COT, Lean Cruise set COT to Disabled. This is mainly to simplify the fuel
tuning…the fewer adders & multipliers involved the better.
Caution: This can damage catalytic converters if you still have them on your car.
Like this:
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Under Spark control
 Open both your high & low octane tables then copy your high octane table to the
low octane table using the copy & paste buttons… this is because once in SD
mode it falls to the low octane table.
 Set MAF fail frequency to 0.
The PCM will detect a MAF fault as soon as you key on and thus revert to speed
density mode.
The PCM requires a MAF DTC to be set to revert into speed density mode. If you
set all of your MAF DTCs (101, 102, 103) to no error reported the PCM will not
revert to speed density.
The factory settings will work but if you are concerned about an SES light, set the
DTCs to No MIL Light. The PCM will still set the code for a MAF fault and thus
still revert to speed density.
 Pop the hood and unplug the MAF sensor. This step is a precautionary step to
make certain that your vehicle does not use the MAF sensor to calculate fueling
while tuning in speed density. It is not required on all vehicles.
Note: If your MAF has a 5-pin plug, your IAT sensor is built into the MAF.
You will need to make provisions to get the IAT signal into the PCM.
Various write-up’s on this can be found at www.ls1tech.com
 Save this tune as SDStarter1.hpt and perform a calibration only reflash of this file
into your PCM.
Data Logging
 Prepare your wideband for use with the usual preheating procedure.
 Start the engine and let it come up to full operating temperature.
 While the engine is warming up, start the HPT Scanner, connect to the vehicle
and start monitoring your data (do not log at this time).
 Once the engine is warm (160° F or higher), start your drive and start Data
logging. Your driving style should be very calm. Avoid sudden throttle changes.
The smoother you can make your driving style while covering as much of the
histogram as you can, the better your results will be.
 It helps to have a passenger viewing the AFR Error Histogram while it is
displaying the cell count. You want to hit as many cells as you can, as many times
as you can. Try to get a cell count of 50+ per cell.
 After you have finished logging data, save the log file as SDtune1.hpl
15
Update .HPT File
 Start the HPT Editor & open SDStarter1.hpt
 Start the HPT Scanner & open SDtune1.hpl
 Open your pre-configured AFR error % histogram & set cell his required to 50,
click average & load all data.
 Next highlight & copy all cells
 Switch to the SDStarter1.hpt file & open your main & secondary VE tables &
paste special-multiply by % to the main & hand blend the surrounding unaffected
cells. Then copy each line to the secondary.
 Now Save your tune as: SDtune1.hpt & perform a calibration only reflash to the
PCM
 If necessary repeat until the average cell values in your AFR error map(s) are
close to 0 (aim for +/- 1%).
 At this point if you have completely removed your MAF & have made the
decision to never use it again you are done and can go about your way. If you are
going to put your MAF back on keep reading.
DIALING IN THE MAF (Combined techniques of Foff/Bill, 12secSS and Cpig)
 To re-enable the MAF simply plug it back in (if you previously unplugged it) and
set your MAF Fail frequency back to its original value and write it to the vehicle.
 Load the MAF - AFR Error.hst histogram.
 You can stay with your current cfg file but all you really need to log is MAF Hz,
Commanded AFR and Wideband. Logging only the necessary items will increase
your resolution which can increase accuracy.
 Make a log while encountering as many "normal" (to you) driving conditions as
possible and a few WOT runs.
 Set minimum cell count for you WB Error histogram to 5.
 Copy the Scanner’s WB error % histogram & paste special-multiply % to your
Editor’s MAF airflow vs. frequency table & smooth. (I hand smooth making sure
I pay extra attention to areas that were not hit during the log run). One technique I
use for this is that I open my original MAF Airflow vs. Freq table and use the
compare feature to bring up the “Show Differences” line chart. I then take out any
sharp peaks and valleys in the show differences chart which in turn smoothes out
my newly corrected MAF vs. Freq table.
 Save & load new calibration
 Repeat if necessary
 Again, the cells in the histogram should get closer & closer to 0% indicating 0%
difference between actual AFR and commanded AFR. As you get closer you can
paste special multiply by % half to avoid overcorrection.
Verification
 Start the HPT Scanner and open the default config file also scan for the WB &
commanded a/f
 Start your engine and the Scan Tool and go for a drive
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


Monitor Commanded AFR and WBO2 AF, they should be pretty close.
Long-term fuel trims should eventually settle in the range –5 to 0
You should also look over & evaluate your injector duty cycle…if your running
over 90% you might want to consider stepping up in injector size.
Finally
After all this you’re ready to start with Spark tuning
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STEP 4
ELIMINATE KNOCK RETARD
(Thanks to Devildog9999)
Knock Retard, or KR is caused by pre-ignition, or detonation. It happens inside the
cylinder, igniting BEFORE it was supposed to. The biggest contributing factor to KR is
heat caused by boost. We need to get rid of all of the KR, NOT just "most" of it.
Q. Is there a "Safe" amount of KR?
A. No. There is a site that says 3-5* is "healthy" - that is wrong, Any KR is bad.
Q. What other things can cause KR?
A. Heat is the obvious one, but it can also be caused by too high backpressure, torque
management, and bad fuel.
Lets open up our scan log, the last one you did that contained a couple of the WOT blasts
we used to tune the trims.
 Open HPT VCM Scanner, open the log file.
 On the histogram, choose the "+" to show MAXIMUM values.
 Click on the Retard Tab and then right click, choose load all data. It should look
similar to this:
This is just to be used as an example. Yours may look different. (Note: The example
shows Cylinder Airmass, however the actual data is KR)
18
Seeing that we do in fact have KR present says that we will have to tune it out. There are
different ways to do this.
Some guys will just tell you to "add some fuel up top" - That will work to quench the KR,
but will in no way enable you to get an accurate tune, with more power in the entire
range. It is a simple way to kill KR - YES, but not the best way.
Now that we know where the KR is present, let’s get rid of it.
 Open up HPT VCM Editor, File, open - choose your latest bin.
 Now go to Engine>Spark Control>Spark Advance>High Octane
Now, looking at our list above, let’s start to tune out the KR.
 Knowing that our KR table shows 2800 X .80 = 2 we can move to the
corresponding cell in the Spark Advance table, and subtract 2 from its value. So the value is currently 15 in that cell, so click on that cell and in the "add" box
choose -2, commit. It will now read 13. This negates KR in that
cell. (Alternatively, you can try removing one-half of the KR value. Most knock
starts out slow and increases. If you prevent it from starting, there’ll be no
knock.)
19




Continue down the list above and remove the KR from all of the cells.
Once you are done, save the table.
Select all of the cells, and copy them to the Low Octane table,
Save the bin, and write it to your car.
REPEAT
 Take it for a drive, and make sure you are easy on it until it reaches normal
operating temperature.
 Log a few WOT runs from "0" MPH to max safe speed. DO NOT DO IT FROM
A ROLL.
 Go through the log file again in HPT VCM Scanner and see if there is still any
KR.
 If there is, then repeat the process until there is none present.
RESET LOW OCTANE TABLE:
 Finally open your low octane table and lower it slightly by multiplying by 0.85
20
STEP 5
IDLE TUNING
(Thanks to ?)
SET DESIRED IDLE SPEED: 900-950 is good for cars with aftermarket cams
 To set idle speed go to VCM Editor>Edit>Engine>Idle>Idle RPM>Target Idle
RPM vs. ECT table and change cell values to desired idle RPM. If idle RPM is
modified up or down, the VCM Editor>Edit>Engine>Idle>Base Running
Airflow>Idle Airflow vs. ECT table must be adjusted up or down also.
 If a lean idle condition is present modifying VCM Editor>Edit>Engine>Fuel
Control>Open & Closed Loop>Idle Proportional Fuel Tables = Off will most
likely eliminate it and any low RPM surging.
SET IDLE SPARK:
 Go to all your spark tables and set the park and drive idle values to about 22
degrees.
SCAN:
 Now switch to a scanner that lets you see IAC counts and TPS voltage. This is
where we will spend some time. We want IAC counts to be 40-60 for cars with
aftermarket cams, and about 60-80 counts for stock cams.
ADJUST IAC:
 To reduce IAC counts turn off the car. Turn the idle set screw clockwise to open
the throttle blade a LITTLE. Unplug the TPS, turn the key to the on position, DO
NOT start the car, for 30 seconds. Turn the key off and plug TPS back in.
 Start the car and begin scanning. Monitor the IAC counts and repeat previous step
until the IAC counts come into line. It will take about 4-6 times to get the IAC
counts correct.
Note: Keep in mind that TPS voltage must be in the .4 to .6 range. If above or below this
voltage, the PCM will fall into the wrong cell at idle. Check the TPS voltage each time
the set screw is adjusted and adjust as necessary.
Another adjustment that will help start-up and idle is to go to the cranking VE table and
multiply the whole table by about 80% to lower it. Now go to the primary or secondary, if
the PCM has it, VE table and drop about 3-6 counts off the idle area.
Open Loop Idle Fueling
The VCM Editor>Edit>Engine>Idle>Base Running Airflow>Idle Airflow vs. ECT table
is like a software choke that is used to control the mixture at idle when the engine is in
open loop. It controls AFR by opening or closing the throttle blade slightly to meet the
values in the cells at a given coolant temperature.
Closed Loop Idle Fueling
For closed loop idle fueling the 400, 800, and 1200 rpm cells at the lowest MAP value’s
in the VCM Editor>Edit>Engine>Airflow>Main VE>Primary VE vs. RPM vs. MAP
table has control over idle fueling.
21
STEP 6
SPARK TUNING / TIMING
(Thanks to Jimmyblue and 03Z06blue on HPTuners Forum)
NOTE: This is one method; however, I believe to correctly tune for Spark, you must use
a dyno to find out where you are making the most power.
PRE TUNE SETUP:
CUT DOWN ON KR AND ADJUST IT TO BRING IT BACK QUICKER:
 In Engine>Spark Control>Spark Retard>Max KR vs. RPM change the limit from
10 down to 5 (2002 WS6s are set @ 4 across the boards stock).
22

On the same screen under Knock Retard Attack, open Base Retard (vs. RPM) and
cut this value in half.
23

While still in the Spark Retard folder, under Knock Retard Decay open Decay
Rate (vs. RPM) and increased the Recovery Rate substantially. Up to 2000 rpm double the recovery rate; 2400 to 3600 - multiply through by 5; 4000+ multiply
by 4. NOTE: Do what you are comfortable in doing. This is what this person did
after a lot of full throttle scanning earlier to get it where he felt safe while
minimizing KR. The values in this screen shot are already multiplied as described
above:
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ADVANCE THE TIMING:
 Open Engine>Spark Control>Spark Advance> Under Main Spark Advance open
the High Octane table. Add about 5 onto the stock HO table. (The numbers below
are adjusted as described)
LOG:
 Drive around and try to put a good mix of throttle positions down, logging Spark
Retard. (You would want to have any TM turned off here or it will obscure the
KR- based spark diddling). Also probably want your KR attack rate reduced and
decay rate increased so the KR is not so prone to overshoot and persist; that also
obscures the true knock situation. (as we did in Pre-Tune Setup above).
ADJUST SPARK ADVANCE HO TABLE:
 Refer to your newly created Spark Retard Histogram. Where you see KR, pull
back a degree and where you don't, add 2 degrees to the Spark Advance HO table;
lather, rinse, repeat. After a few sessions of this sort you should have a histogram
that's all 0-1 degrees of max spark retard.
 Now subtract 2 degrees across the board and you'll have a good, safe (for the
present mods) tune.
REFINE LOW OCTANE TABLE:
 Finally, copy the new HO table to LO table and subtract about 4 degrees from the
LO table at .40 g/sec rows and higher, just so you have some sort of safety net for
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bad gas or bad weather. (Another method is to subtract 15% by multiplying the
LO table by 0.85).
MISC THINGS
DELETING REAR O2 SENSORS:
In Editor, go to ENGINE DIAGNOSTICS>DTCs
Under the far right column under Error Mode set these to “3-No Error Reported”
Driver Side
137 - HO2S Circuit Low Voltage Bank 1 Sensor 2
138 - HO2S Circuit High Voltage Bank 1 Sensor 2
140 - HO2S Circuit Insufficient Activity Bank 1 Sensor 2
141 - HO2S Heater Performance Bank 1 Sensor 2
420 - Catalyst System Low Efficiency
Passenger Side
157 - HO2S Circuit Low Voltage Bank 2 Sensor 2
158 - HO2S Circuit High Voltage Bank 2 Sensor 2
160 - HO2S Circuit Insufficient Activity Bank 2 Sensor 2
161 - HO2S Heater Performance Bank 2 Sensor 2
430 - Catalyst System Low Efficiency Bank 2
Diagnostic Trouble Code (DTC) Error Modes:
0 - MIL on First Error: Emissions related. Illuminates MIL the first time DTC sets.
1 - MIL on Second Error: Emissions related. Illuminates MIL if fault is active for 2
consecutive driving cycles.
2 - No MIL Light: Non-emissions related. Does not illuminate MIL, but will illuminate
SERVICE light.
3 - No Error Reported: Non-emissions related. Does not illuminate MIL or SERVICE
light.
Diagnostic Trouble Code (DTC) SES Enabled
On: Enable SES lamp for this DTC
Off: Disable SES lamp for this DTC
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