Please don’t change the title of the email, it helps keep me organized.  dont go wide open throttle (WOT) yet.  Make sure your AP Manager is updated to the latest version. You have to flash using the handheld unit. Always flash as a permanent map so the realtime tables don’t get deleted in case of power loss or battery disconnect.

Basic Tune Process Outline

2-4 cruise logs dialing in low load air fuel ratio (AFR)
5-10 wide open throttle logs (all 3rd gear, increasing rpm every revision)
1-3 beating logs. (all gears, all types of driving)

First Logging – Cruise Logs

Please don’t change the title of the email, it helps keep me organized.  Don’t go wide open throttle (WOT) yet.  Make sure your AP Manager is updated to the latest version. Go to the “Logging Setup” screen and check the boxes next to the parameters listed below.  To access the logging setup screen press up on the gauge screen then enter.

Load up the attached map, get the car up to operating temp (Coolant Temp 170* or higher) and then Datalog the following parameters for ~5-10 minutes.

While datalogging, drive in the entire closed loop range. Basically up to 75mph, no wide open throttle.  Basically just drive at all different speeds with as little throttle movement as possible.

Keep rpm less than 4000 rpm.
Keep throttle as steady as possible.
Drive at 75 on freeway with constant throttle.
Drive at low speed with constant throttle.
Idle for 2-3 minutes back home.
All data is good data as long as the coolant temp is above 170*.
Stop log and send me the file.  Just log everything in one file, do not break it up into multiple logs.

When I ask for a Wide Open Throttle pull.  ONLY DO 1 PULL.  MULTIPLE PULLS MAY CAUSE DAMAGE.

During the tuning process, you must only cruise around when not logging.  DO NOT BEAT ON THE CAR DURING THE PROCESS.

Please don’t send me screenshots of your AP.  They are useless and I will just ignore the email or text.  Send me a log.

2015 WRX Log List (to set this up press up on the gauge screen to enter setup and select the following parameters)
AF Correction 1
AF Learning 1
AF Sensor 1 Ratio
AVCS Exhaust Left/Right
AVCS In. Left/Right
Calculated Load
Closed Loop Sw.(on/off)
Coolant Temp
Dynamic Advance Multiplier
Feedback Knock
Fine Knock Learn
Gear Position
Ignition Timing
Injector Duty Cycle
Intake Temp
Intake Temp Manifold
MAF Volt
Requested Torque
Target Boost
Throttle Position
Wastegate Duty

2015 WRX Post Flashing and Warmup

After you start the car it takes the front 02 sensor 60-90 seconds to warmup, even if the car is warm.  So it’s best not to just start your car and start beating on it because the AF learning and corrections may not be active.  You can monitor this by monitoring AF Sensor 1 Ratio on the AP.  When you first start the car the AFR will stick at 14.7 until the 02 sensor has warmed up.  Once the AFR has moved from 14.7 and the AF Correction1 are AF Learning1 are active, then you know it’s ok to log.  You need to be really careful about beating on the car before the sensor is active, running lean will cause knock and could potentially blow the motor.  You can see an example of a non-warm 02 sensor below...the AFR sticks to 14.7 until 5800rpm.
After you flash a new map the AVCS also has to go through a warmup/activation procedure.  You can monitor this by monitoring AVCS intake.  It will go -5, -4, -3 -2, -1, 0, 1, 2, 3, 4, 5, then back to zero.  It basically goes through a calibration to make sure it knows where the cams are at after you flash a map.
Also, during startup the stock mapping retards the timing to -15* which causes the loud noises during cold start.  These timing maps are not defined in the Cobb software.  After a period of time, the timing will jump up to 5-10*…this timing jump causes an rpm fluctuation.  Once the 02 sensor comes online, it can also cause an rpm fluctuation.  So there are 2-3 periods during startup that may cause an rpm fluctuation that simply can’t be tuned out at this time.

2015 WRX Launch Control

** I do not recommend utilizing launch control nor flat foot shifting unless you are racing in competition for money and on race gas. It puts the engine in a lean condition and can cause large knock counts.  It is not worth the wear and tear if it is your daily driver.  **

Rpm adjustable via “Tune” menu then “ECU Adjustments” then “Launch Control”
Rpm also adjust via Cruise Control buttons on the steering wheel.
Launch Control can be set with the clutch in, then press the gas and hit the cruise control set switch down (Set).  The Cancel button will cancel the LC and let you free rev.  Pushing the SET option will reset the LC to the current RPM.
Flat Foot Shifting (FFS) is also set via the AP.   Rpm is adjustable via “Tune” menu then “ECU Adjustments” then “Flat Foot Shifting”
2015 WRX Knock & FAQ

- FLKC or even FBKC during low load cruising is not an issue.  It will happen periodically from AC on/off, quick changes in throttle, bad gas, environmental changes, etc.  It’s bad to take all the timing out of the car.  The random cruise knock is just the knock control system doing its job.  The thing to look out for is 2 counts of knock at WOT....anything -2 or more and you should report it back to me with as much detail as possible (gear, rpm, did you just fill up with new gas, elevation, were you sitting at a light, stop sign or traffic directly before, heat soak, etc).

- Be aware that FLKC does not mean you are knocking all the time.  FLKC is LEARNED knock, so the ECU stores it and every time you pass through those same RPM v Load cells the FLKC will appear until the ECU unlearns it, which will happen if you pass through those load cells knock free for xx number of cycles.

-  Be aware that each line of knock in a log is not actual knock.  Only the initial -1.05 or -1.41 is a knock event.  The next 10-100 lines of knock are just the algorithm in the ECU waterfalling the knock to 0.  So it will go -1.41 for several lines, then -1.05, then -0.7, then -0.35, then back to 0.

- Also, reset your ECU as little as possible.  If the ECU has learned knock (FLKC) and you reset the ECU constantly, then the car will have to knock again for the ECU to relearn.

- I suggest only using top tier gas stations.  My favorites are shell and chevron in that order.

-  Cobb’s knock faq http://www.cobbtuning.com/subaru-knock-monitoring-and-dit-knock-logic-changes/

-  Knock writeup by Innovative Tuning http://www.innovativetuning.com/subaru-ej-vs-dit-engines-critical-changes-in-knock-control/

-  TGV Deletes and EGR Deletes are 2 of the best mods for almost entirely getting rid of all cruise knock.  These 2 mods really open up the intake manifold flow and reduce charge air temps by 70-100*.  While you’re cruising at low load between 2000-5000 rpm the ECU is opening the Exhaust Gas Recirculation valve and injecting hot exhaust gas into the intake manifold.  This causes a huge increase in the temperature in the manifold, which can be monitored via Intake Temp Manifold.  This large increase in air temperature is one of the main causes of “cruise knock” and/or “tip in knock”.  Since the charge air temperature is abnormally high it puts the car in a highly knock prone situation.  If a very unfavorable situation occurs the car can pull a -8 to -10 FBKC due to the extremely high intake temps in the manifold. 

-  These next pictures show what knock looks like on the stock tune on 91 octane.  So you can see that the occasional instances of FBKC and FLKC are substantially reduced from the stock tune.  You can see that the Dynamic Advance Multiplier (DAM) is down to 0.312 from 1.0.  This means that the car is only running 30% of the ignition advance because it is knocking so badly.  And the car is also pulling -7* FBKC and a little FLKC.  A single 5 minute cruising log had 13,286 lines of knock.  Again, this is shows how poorly the cars run on the stock tune and how insignificant a couple -1.4’s are once tuned.


- Oil – I use rotella t6 and change every 3000 miles with Subaru filter and crush washer.  Many people’s oil analysis have shown large amounts of fuel in the oil, so it is best to change the oil often to avoid degradation and bearing failure.  Other folks have been happy with Motul, Brad Penn and Amsoil.

AF Correction & AF Learning Monitoring

Monitoring these 2 variables on the AP and just looking at mins, maxes and screenshot data is mostly pointless.  These 2 parameters are constantly changing due to gas, temp, humidity, rpm, etc.  To look at the data correctly the Correction and Learning need to be added together and looked at over time.

You can see in this set of data that the total correction (AF Correction 1 + AF Learning 1) can come out to be -6% to +9% over a collection of data, but the overall interpolation of the data (the black line) is basically right around 0.  This is what an normal car looks like.



This next graph is what a car with leaks looks like.  Notice the wide variance in total correction from -22% up to +22%.  This is very abnormal and is usually good evidence that the car has a leak.  The wide range in corrections comes from passing through the same MAF voltage in vacuum or in positive pressure, which changes the way the leak effects the fueling.  A post turbo leak will make the car run lean in vacuum and rich in boost.  A leak between the MAF and turbo will make the car run lean in vacuum and lean in boost.









Here is an example from a log where looking at screenshots on the AP of the AF Correction and/or the AF learning would give you false/misleading information.  You can see here that the car learned -8.59%, but is correcting +8.59% at the same time….so the total correction is actually 0%.  In the lines of this log, the greatest total correction is 1.57%....yet the individual learning/correction are very high.


In this screenshot you can see that the individual Correction and Learning values are lower than the pic above, but the overall correction is greater than the pic above.  So the data can be misleading unless you look at it correctly.

 Catted vs Catless Downpipes in Cold Weather (Boost Creep)

Running a catless downpipe can cause boost creep in cold temperatures.  Boost creep is when the boost uncontrollably rises at high rpm.  Boost creep can NOT be tuned out, it is a mechanical issue from running a catless exhaust.  You can see in the picture below that the boost line with the catless exhaust rises uncontrollably after 5000rpm.  This boost creep is typically only seen with a catless exhaust + intakes in temperatures below 40*.



High Ethanol Content and Monitoring the Fuel Pressure

The fuel pressure is continuously varying depending on rpm and boost.  It is around 300-400psi when cruising around and ~2200-2500 psi at wide open throttle.  If you’re running high content ethanol (e70-e85), the high pressure fuel pump (hpfp) can start to act crazy and not supply the targeted fuel pressure.

When it starts going bonkers, the fuel pressure will just start jumping all over up and down.  You will be cruising at it will go from 300 up to 2000 then down to 50 and keep oscillating like that.  You will be able to feel it...it will feel like slight jerks.  You can stop this behavior by adding some pump gas to the car, or by resetting the ECU.  Resetting the ECU is only a temporary fix.

Rear 02 Sensor Codes to Turn Off For Visconti’s Flex Fuel Kit

P0037 – H02S Heater Control Circuit Low (Bank 1, Sensor 2)
P0038 – H02S Heater Control Circuit High (Bank 1, Sensor 2)
P0137 – 02 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
P0138 – 02 Sensor Circuit High Voltage (Bank 1, Sensor 2)
P0141 – 02 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
P013A - HO2S Slow Response Rich to Lean (Bank 1, Sensor 2)
P013E - HO2S Delay Response Rich to Lean (Bank 1, Sensor 2)
P113A –
P2270 -  O2 Sensor Signal Stuck Lean (Bank 1, Sensor 2)
P2271 - O2 Sensor Signal Stuck Rich (Bank 1, Sensor 2)


IAG or TIC TGV Deletes
TGV deletes greatly reduce cruise and tip in knock.  They also produce around 10-15whp across the whole powerband.
TGV Codes to turn off
P2004 through P2022

IAG EGR Deletes
EGR deletes help eliminate carbon buildup on the valves and they can also reduce charge air temps by up to 100*.
After EGR delete install it is imperative to bleed the coolant system as you have introduced air bubbles which can cause overheating.
EGR Codes to Turn Off
P0400 – EGR Flow
P1492 through P1499 – EGR Circuit High/Low

IAG Air Oil Seperator (AOS)
AOS help eliminate carbon buildup on the valves.
After AOS install it is imperative to bleed the coolant system as you have introduced air bubbles which can cause overheating.
All AOS’s suffer from “sludge”.  They attempt to prevent this by running coolant through the can to heat the system, but the return line is not heated.  When the temp drops below 40*, moisture will accumulate in the return line and then mix with the oil and form the sludge pictured below.  This sludge is extremely common in cold temperatures and even more prevalent when using e85.  Running an AOS requires you to check this and either clean or replace the hose.  It is also ideal to run 3,000 mile oil change intervals.

Process West Verticooler
The PW TMIC decreases the charge temps by 40-60* vs the stock tmic and can make 30-40whp more than the stock TMIC at high rpm.

Grimmspeed Electronic Boost Control Solenoid (EBCS)
EBCS will produce a smoother boost curve and hold boost better in the midrange, thus picking up hp/tq through having a better and more consistent boost curve.

Coolant Bleeder
basically put the funnel in, fill halfway with coolant, start car, let the car heat up until the fans turn on, then turn on heater, then blip throttle until bubbles stop. let car cool with funnel in place. Restart car and repeat one more time

submit NASIOC feedback here

Picker buyer from the dropdown
Pick positive
Make a short comment
Copy this for sale thread into the deal thread space  http://forums.nasioc.com/forums/showthread.php?t=2263927
Copy your short comment into the additional comments box

Yelp Feedback

Facebook Review, Like and follow

PhatBotti Review Thread


YouTube Channel

gtx35 build thread

E-Tuning Prices and What You Need

Dyno Tuning




2014+FXT/2015+ WRX

Instructions & FAQ

PhatBotti Tuning