Ok i just had a local shop make me an 02 housing and ever since i got it back my idle afr's are stuck at 18-21 sometimes 21 steady. I did a boost leak test and fixed my leaks, that did nothing. So i made sure i didnt have any exhaust leaks before the front o2 sensor, only thing that i found was one of the 4 bolts that holds the turbo to the manifold is broken, but its been broken for the past year with no issues. I know the sensor is reading right since all my plugs are white. So now im stumped and dont know where to go from here. O and the iac is fine and the resistance values are within spec. Any help or guidance is appreciated

 

anyone?

 

What are afr at full throttle? pig rich? could have fried the o2 sensor from the heat if they torched it out, or if they welded it when it was on there

 

At wot afrs are around 11 and 14.7 while cruising

 

i had the same problem but mine was the fuel filter was clogged and i had a bad fuel intake grommet that was causing low fuel pressure also... i would make sure your injectors are clean and your fuel filter is not clogged or replace it if you never have. Do you run E85 by chance?

 

im on 93, ok cool ill check that thanks

 

you most likely have small exhaust leak at your new custom 02 housing. fresh air will lean out your wideband

 

im having a similar issue. My a/f ratios are fine except at idle. At idle they are very erratic and tend to be more lean.

 

That's what I keep thinking but I haven't been able to find one

 

also i should mention that the plugs are white, so my theory of the wideband reading wrong is shot

 

Did you find a solution? I´m having the same issues with an Evo 7 and it´s driving me nuts

Thanks for your help!

 

nope the sock filter is clean, there is an internal filter in the pump carrier that isnt serviceable so i cant check that, so its either a fueling issue or my custom dump is leaking which ill find out when i find time to put the oem back on, ill update the thread once i find the culprit

 

Revival.

Did you ever solve this? I'm having the same issue