Hey guys,

I've been having this issue with my evo lately. The car threw a P0172 (system too rich) code. Oridinally fixed by CBRD which was a TB leak, well we thought it was fixed. The IM was replaced with a BR ported stocker and the TB replaced with a Mil spec 65mm unit. The code didn't come back and CBRD did a new tune for the car.

I picked up the car and the next day, the code returned. The car was taken back to CBRD about a week later and has been there for about a month now. No matter what we do to the car, the ecu changes the fuel trims. From what Chad was telling me, the only time it doesn't is at WOT.


Things we have changed with no luck:

02 sensors
MAF sensor
BOV
injectors
walbro fuel pump
battery
changed the TB to a stocker
compression 170-175 accross all cylinders
changed all the solenoids on the IM
retuned
temperature sensors checked.
Fuel pressure regulator, evap sole and check valve, throttle body, idle stepper, EGR, plug wires, MAF, bov, head gasket, pcv valve
ECU swapped out

It's obvious I can't tune cars, sorry if my lingo isn't correct

I'm sure there are other things that Chad and Mark have done, but we are kind of stuck at this point.

I was wondering if anyone has had this issue with the stock ECU changing the fuel no matter what?

Any help would be great.

Thanks

Jason H.

 

I wonder if tuning the ECU too much can cause this problem. I think I'm going to stop tuning the ECU after I finish tuning my new turbo. Hope you'll get your problem fixed.

 

I highly doubt it's from "tuning the system too much". My car has only been tuned by CBRD and Chris@AMS. Maybe 4-5 times.

Hope it gets fixed as well. Thanks

 

I talked to Chad about your problem when i was down there..... its a wierd one for sure. CAn you post anything more one what happened when the problem occured. Does the car run and dive fine but the CEL comes on, did it have an issue and happen all at once o get worse over time. the ore details the better

 

maybe Chad can chime in with more info on what the fuel trims are doing.

 

Chad can explain a lot more than i can. He has been great keeping the car for me & squeezing the car in every second they have.

Car never had any issues besides this happening besides some spark plug issues after the BBK instAll. The car didnt feel right after getting it back this last time & then it would idle badly almost stalling frequently.

Im up for any suggestions.

 

What did you have done when you say *the last time*. scheduled maintenance, tune....??

 

the following have been replaced:

Fuel pressure regulator, evap sole and check valve, throttle body, idle stepper, EGR, plug wires, MAF, bov, head gasket, pcv valve, almost everything i can think of...

we did a compression test... 170-175 all across....

as soon as the primary is warm, the trims go full negative, then trickle back positive, then negative.... we have the stock injectors back in, another fuel pump, everything...

hmmmmm


cb

 

What intake is on the car? It sounds like there is a vacuum leak somewhere; but man you've replaced almost everything.

 

GOT IT!!! change the oil Chad! LMAO......inside joke

On a serious note Maybe the wires at the maf connector are loose. With how much stuff has been replaced it seams as tho the issue might be in the harness somewhere.

This could be way out there but In fuel injection class we had to diagnose a fualt within the ecu that caused improper refrence voltages out of the ecu. Just trying to come up with some stuff you haven't already listed checking.

 

Try loading in a totally different stock rom image

I have seen roms pick up corupted data

Also - maybe I overlooked this but what kind of BOV is on the car ? - Re-circulating I hope

Al

 

Al,

thanks for the input.

i used an entirely different ecu with the immob copied over... same thing...

stock evo ix bov recirc'd

cb

 

Thanks everyone for taking a look @ my problem. Im sure its going to be something so small. I totally owe the crew up @ CBRD lunch. Well, maybe not Caleb. Jk buddy ; )

 

Which intake tube is on there?

 

whoa whoa whoa... watch it pal