I originally posted this problem in the UTEC thread, but it really didn't apply to that section. The car is a 2001 Impreza L w/axis stage 2 block/v7 sti ra spec c heads w/avcs/ v7 ecu. Alright here is my problem. My car is reading an incorrect air/fuel ratio. The car thinks it is running 11.8 when it is actually running a little above 13 (the laptop hooked up to the utec said the car was reading 11.8), but while getting dyno tuned the a/f reader the tuners had said my car was running above 13. This is a big problem because even if the tuner tried to compensate for the difference in a/f ratios the car would eventually change the tune because of the way the ecu learns.

I believe the problem lies within the wiring because when the electrical was done it merged the gc harness with the engine/pcm part of the v7 harness. The 02 sensors were replaced a month ago. So it appears that my only option is to have my wiring traced to figure out where the problem is. This could get expensive depending how well the electrical swap was done (I bought this car modded). Also the rev. 6b UTEC I have reads everything from the car, but the car will not respond to changed in fuel values.

So I am thinking that that if the wiring issues can be resolved I should wait for the new AP to come out because it will be able to work with JDM ecus and can tune for AVCS. The only other option I can think of is running a standalone ecu, which is more than I am willing to spend. I will not be able to do any of this electrical work myself and diagnostic work is $50/hour at the shop I go to. If anyone has any advice I would appreciate it because I really am clueless about this stuff. Sigh...I just want to drive the damn car. Oh, and the ecu has an ecutek flash on it according to the previous owner. Also on the dyno I was experiencing some detonation so I can't drive the car like this. The baseline pull we did showed 333whp/333wtq untuned so there is a lot to be had from this setup.

Also with the detonation issue: if I put higher octane in it will I be able to drive it w/o detonation?

IIRC you can already tune JDM ECUs with the OpenSource tools, why spend money on a AP? About the wiring issue though, it could have the wrong O2 sensor installed or a failed O2 sensor. I am sure someone else will chime in but I thought the JDM ecus needed a JDM O2 sensor (I could be wrong though)

Also, was your AFR readings during a run or idling? The ECU will not attempt to correct AFR ratios when the UTEC takes control during a run. Also, how can you be sure the tuner's Wideband sensor is accurate? Don't they usually stick the sensor in the end of the exhaust? A possible exhaust leak would make it read wrong at that point.

with the detonation issue, it may be possible depending on how bad the detonation is and what is causing it. If the octane is high enough it won't detonate

The afr readings were during a run and idle I believe. The cars readings stayed constant. Your exhaust leak point is interesting and I will look into that. I'm also going to look into the possibility of needing a jdm 02 sensor. Thanks for the input.

Also, will most tuners tune with the open source?

IIRC you can already tune JDM ECUs with the OpenSource tools, why spend money on a AP? About the wiring issue though, it could have the wrong O2 sensor installed or a failed O2 sensor. I am sure someone else will chime in but I thought the JDM ecus needed a JDM O2 sensor (I could be wrong though)

Also, was your AFR readings during a run or idling? The ECU will not attempt to correct AFR ratios when the UTEC takes control during a run. Also, how can you be sure the tuner's Wideband sensor is accurate? Don't they usually stick the sensor in the end of the exhaust? A possible exhaust leak would make it read wrong at that point.

with the detonation issue, it may be possible depending on how bad the detonation is and what is causing it. If the octane is high enough it won't detonate

I am really hoping that the problem is that I have an exhaust leak and that's why the readings were different. The UTEC was reading the ecu, but wasn't able to alter anything. I'm hoping that problem is because of conflicts between the ecutek flash and the UTEC.