[wasta2424]

hi folks,
last year i had a problem that I fix, I was overboosting(vaccum leak from the westgagte)

This year, im run running rich!!
my car is tune right and I dont have news mods

running catted exhaust, up pipe, vf39, sti manifold with cobb,accesport, sti intercooler, sti injector.

THe issue that i have is not permanent. Run great at idle and great when I drive around. but when I pull a little bit harder, my car goes rich, at idle, normal speed, pull etc, rich everywhere . aem afr read 10, and accesport read 11.4( datalog)all the time. no matter what I do, it just dump gas, smell gas a lot, stall twice etc


first of all, should I trust ap afr or aem wideband?
where should I start search?

already check couple of things... im little bit lost right now

 

[wasta2424]

09 wrx sedan.. thx for help

 

[SD_GR]

Hello, I've edited the title of your post to make it appropriate according to our rules. Good luck with the car.

 

[wasta2424]

Someone ??

 

[Steemax]

Well, when were you tuned? Quite possible you were tuned with the boost leak.

 

[Whitefang]

Post some logs for us

 

[MainFrame]

This year, im run running rich!!
my car is tune right and I dont have news mods

THe issue that i have is not permanent. Run great at idle and great when I drive around. but when I pull a little bit harder, my car goes rich, at idle, normal speed, pull etc, rich everywhere . aem afr read 10, and accesport read 11.4( datalog)all the time. no matter what I do, it just dump gas, smell gas a lot, stall twice etc


first of all, should I trust ap afr or aem wideband?
where should I start search?

already check couple of things...

There are a few different things it could be. As far as which sensor to trust, it kind of depends on whether the discrepancy is during boost or not. The front AFR sensor (in the manifold) isn't calibrated to read correctly under higher manifold pressures. If the discrepancy is at idle/cruising then it could be either one.

Have you talked to your tuner, and do they have any ideas as to what might be going on?


What does the car idle at if it's just sitting and warmed up? Do the readings from both sensors under those conditions more or less match up? Since you're smelling raw fuel (assuming there are no fuel leaks) and the car is stalling it's probably safe to say it is indeed very rich. After you had the vacuum line on the wastegate fixed did the car run right for some period of time? Did this rich condition issue just start suddenly? Was anything on the car changed before the issue appeared? What have you tried doing to diagnose the problem thus far?


First things I would do to trouble shoot would be to clean the MAF sensor, and perform a boost leak test from the elbow on the intake all the way down stream. Make sure there are no leaks. ~20psi should do it. I would also check the voltage of the MAF sensor in the logs to see if it appears to be working correctly. Check the exhaust for leaks too.. a Seafoam treatment usually works well for this since it will cause the car to blow smoke like crazy. It's not uncommon to see a little bit of smoke from around the wastegate arm, but if anything comes out upstream from the sensors then you have a problem. I would also inspect all the electrical grounds in the engine bay and clean them up as needed just for good measure.

Other places to look would be fuel pressure and injectors. You can get a fuel pressure gauge pretty cheap, and to check injectors I would start by pulling the plugs and looking at the tips to see if one cylinder appears to be running significantly richer than the others.



Completing all of those tasks could be done in a day and should cost less than $40 total (assuming you have access to an air compressor). That is if you don't uncover the problem before finishing everything.