Sorry to hear this still hasn't been resolved Cali. I know how you feel being without your car, mine has been down for almost 3 months.

What do you plan on doing with it in the future? You gonna drive it like that or get rid of it?

 

If i had someone buy it, I would. But I'm not the type of person to sell someone a car that has a known issue. I think it might be an electrical problem, so I'm going to get someone to check out the electrical system. Maybe it's a short in the wiring harness. Who knows??

It wont pass anual PA inspections UNLESS i use one of tephra's mods to get it to pass and bypass the p0172 code. It's sitting in my garage right now for the first time in 4 months.

Thanks Chad for attempting to fix it.

 

Sorry to see that you've been without the Evo for so long. I've been following this thread in case it happens to me. I'll throw out two thoughts I've had since nothing else seems to work. Have you checked out the TPS? I didn't see it mentioned in the fixes you and Chad have tried. A defective one will do crazy things to the fuel. Even further away from the "normal" glitches, my Evo 8 was getting really crappy fuel mileage, and running wierd at times. I discovered that the (dealer installed) boost gauge source is a T-fitting in the short vacuum line from the intake to the fuel regulator. The rubber hose is so short and curved that the T-fitting actually forced a crimp in the rubber line and pinched off the flow of vacuum to the fuel regulator. I replaced the T with a Y type fitting and eliminated the crimp. That solved the problem for me.

Again, sorry you're having such problems, but be sure and let us know when you solve it. I have no doubt that Chad (and every one at CBRD) has lost a lot of sleep over this and won't give up until an answer is found. Good luck!

 

does the evo have a fuel pump gasket??? my STi had a fuel issue and it was that

list the mods that were done to the car; do you have an intricate electrical system; do you have your grounds checked and rechecked? fuel pump grounded out?? if not you should do that

 

ANy vacuum leaks, that would thow off the AFR and cause the LTFT to shoot more fuel into the car causing the O2 to read it rich.

 

No boost/vaccum leaks. I actually wish it was that easy

 

CB,

You just described the exact same thing I am experiencing with my car in closed loop. I disabled the P0172 code on the ECU and disabled closed loop in the periphery. It helped as an intermediate solution, however I am yet to find the damn culprit.

 

i believe when i had the problem the spark plug fouler trick on the rear o2 sensor fixed it. does anyone else remember having this problem

 

I already have a rear 02 sensor anti-fouler PLUS its "system too rich, bank 1". The primary 02 sensor was replaced and the problem still persists.

Thanks for trying to help

 

bump for the op

 

Its weird driving the car. It resembles a BOV flutter at low rpm (no boost). I need someone to disable the code/closed loop. Would this get me past state inspection??

 

I had a similar problem that threw the P0172 CEL. Turned out to be an exhaust gas leak at my O2 housing. Might want to check for an exhaust leak. One of the bolts on the O2 housing fell out... installed new bolt and seal, fixed my issue. Just an idea you might want to check.

 

Turbo and exhaust was taken off. No exhaust leak. thanks for the suggestion

 

i had somewhat similar problem but it was in my tune. car would get short fuel trim and then zero out. My problem was some perhipheal bit or however you spell it was disabled in my ecu. I see that they did a new map for you so i guess thats not the issue but it worked for me. We enabled that bit and then we were able to do fuel trim.

 

Chad, send me his ROM image. I can turn off closed loop and the p0172 code just to see if that helps him.

I honestly think it is his MAF. We can switch it over to SD if you have a JDM 3 bar laying around to through in it to test?

email me at phenem at gmail dot com