mrm95

iTrader: (1)

Lately on my Evo 9 the p0171 code has been popping up. The car is bolt ons and E85 on stock turbo. So the first time i noticed the code pop up was a few weeks ago (at first i was really freaked out because it was right after i did an oil change.) so i went to get the code checked and it was the p0171. So then i figured it was a vacuum leak and found a rip in my stock UICP coupler by the throttle body. So i got a short route UICP and small battery kit. I installed those and at first the car was idling really lean so i boost leak tested it and a couple couplers were leaking a very small amount so i tightened them and that took care of the leaks. But the car when coming to a stop or when im first idling will still be really lean then eventually fall down to where its suppsoed to be. Cruising and WOT AFR's are where they are supposed to be. This morning it seemed like the car was idling a little off ( sounded like it was skipping a beat here and there.) i figured it was just me being paranoid. Then while driving the same p0171 popped up again. This is right after i boost leak tested the car and assured that there were 0 leaks. Im pretty lost at this point on what to do. What else could it be? I was thinking maybe the o2 sensor or maybe the injectors need cleaned.

Fox5.56

Try your EGR valve?

mrm95

iTrader: (1)

Could that be it? if so i have a block off plate

mrm95

iTrader: (1)

Anyone else know what it could be? Other than a vacuum leak