need bb Posted December 20, 2016 Share Posted December 20, 2016 I was recently tuning my car and after completing some 3rd gear pulls I noticed my AFR correction was at -25% at idle. My AFR corrections are usually within 5%, so I am trying to figure out what changed. At first I thought my O2 sensor was shot, but my wideband matched the O2 sensor. This sounds like a boost leak, but I thought that they usually caused the car to run lean instead of rich. Any ideas would be greatly appreciated. Link to comment Share on other sites More sharing options...
ehsnils Posted December 20, 2016 Share Posted December 20, 2016 A fuel injector that doesn't close completely. Or the MAF that's dirty. Link to comment Share on other sites More sharing options...
Silinc3r Posted December 20, 2016 Share Posted December 20, 2016 If it is a boost leak, the boost gauge should show zero. Silinc3r's 05 SWP GT/Spec B Link to comment Share on other sites More sharing options...
CapnJack Posted December 20, 2016 Share Posted December 20, 2016 Shot in the dark... What fuel are you tuning on? If it is E85, they have gone to winter blend and your car will run rich due to the decrease in Ethanol content. Link to comment Share on other sites More sharing options...
need bb Posted December 21, 2016 Author Share Posted December 21, 2016 Running 91, but good guess is I was running E85. I will trying cleaning the MAF to see if that helps. Is it true that a vacuum or boost leak would cause the car to run lean instead of rich? I hope it is not the injectors. Got them cleaned and tested a year ago. Thanks Link to comment Share on other sites More sharing options...
CapnJack Posted December 21, 2016 Share Posted December 21, 2016 Yes - A vacuum leak would typically cause car to run lean. Are you seeing a rich condition across all fuel trim levels (ABCD?) or just on A? Are you running stock fuel pressure regulation? I have seen high fuel pressure at idle cause a rich condition as well. Does it idle properly or does it seem to stumble on a cylinder? Link to comment Share on other sites More sharing options...
need bb Posted December 29, 2016 Author Share Posted December 29, 2016 Wanted to provide an update in case others have a similar issue in the future. Cleaned the MAF and the issue seems to have been fixed. My fuel trims are off a bit, but that is party due to scaling my MAF when it must have been slightly dirty. Link to comment Share on other sites More sharing options...
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