Hey guys, I'll try not to do another cookie cutter "unplug maf car runs fine" post and I promise this is more then that but I've searched for days and although many have posted this, none that I've found have done what I've done or really post their end result. Here's my info. 2004 wrx, 68k original miles, regular mods including headers, catless up and down, 3in back, as well as a cheap cai unfortunately. Ebc from grimmspeed, oversized tmic. Story on the car previous life. Bought it from a guy somewhat close by who did open-source tuning himself. Seemed to really know his stuff and the car ran good when I got it. A couple months went past and I started to notice a slightly erratic idle as well as a misfire when cruising at low acceleration. Nothing too major but noticeable. Afrs according to my wideband were jumping around lean to rich but would even out under boost so I looked past it. Then one day it started leaning out under boost. Took fuel pressure numbers and got mid 30s at idle. Decided to replace the filter and pump with a walbro unit which brought my pressure numbers back up but didn't help. After this the idle slowly got worse. it's to the point where it will start, run for a second and die. You can keep it running with the pedal but barely and afrs are lean 16-17+ unplugged maf and boom runs great. So I did a boost leak test and fixed a couple small ones. As well as smoke tested for vac leaks after and found none. No difference in idle. Replaced maf with a returnable reman. No difference. Pulled plugs and all looked fine with good color, but replaced anyways since I had them out. Also replaced front o2 with a new denso that I had. Same problem exists. Short term fuel trim at 25+. Won't run with maf plugged in, runs great with it unplugged with steady afrs (which I've never seen at idle with this car) at 14.8-15.2. I'm at my wits end with this issue. Does anyone have any other ideas before I bring this to someone and get reamed with diagnostic fees? I feel very confident in my repair skills and this is driving me insane.
And yes I reset the computer after each repair. Upon reading my post over, I guess it's possible I got a bad reman maf?
