it seems like the wb02 may be off for some reason... the nb02, 02feedback and low trim are all within spec...the ecu thinks the AFR is fine. Are you sure you don't have an exhaust leak near the wb02 sensor?

 

I'll check the exhaust connections this weekend, but wouldn't the leak only come from the connections on the downpipe/testpipe, basically upstream before the sensor? I just had the clutch replaced so they had to take off the dp and put it back on, but the thing is that i was having this problem both before and after the install. Also I'm pretty sure I took off the dp and put it back on as well. As a note the wideband is bunged into the test pipe. Also I noticed a few things, when the gauge shows the a/f ratio leaning out, that is when the car lopes the most. After thinking about it, its not really that much more than before, I just notice that the idle seems to get more bumpy when the gauge reads more lean, but as I said in previous post, nothing else is off, my cruising a/f ratios are right where they need to be, and during WOT everything is fine as well. Could it possibly be a front O2 sensor going bad? I know that during idle it runs off of that sensor, or does the data in the logs not back up that theory. Thanks again for all the help guys, especially mellon.

 

less time talking, more time checking for boost and exhaust leaks

 

well I just did a boost leak test and there are no leaks, I can't do the exhaust test until this weekend, I'm up at college and don't have any place to jack the car up, but will be home this weekend, where should I look for the exhaust leak, any place in particular?

 

header, turbo, 02 housing, downpipe, cat/test pipe

 

not sure which intake your running, but make sure its not missing any vacuum plugs or vacuum lines. thats not something that ever gets tested when doing a boost leak test and is easily overlooked. such as the line that goes from the intake to the valve cover....

 

was this resolved?

 

i started to have lean idle also, the car even died during heavy traffic, my AEM afr gauge reads lean when this happened, also notice when full throttle my AEm showed afr leaned a bit first then only gets back to normal afr.

Also my fuel pump sounded a bit funny when the lean idle happened, could this be Fuel Pump issue? Had my walboro installed early this year.

 

Can anyone help to give advise?

 

did anyone fixed the lean idle
am having the same problem

 

Sorry to bring back from the dead but I just wanted to clear up that the problem was a leak in the flex section of the downpipe. Flex section replaced, and now the wideband reads perfectly again. The evo runs awesome now!

 

^^ Good News ...

 

I don't get where the leak is coming from, licp couplin or the turbo it self??

I also would like to know if lean idle can be harmful to the motor?