Just got retuned about 2 months ago and now the car is starting to run lean at around 12.3 under WOT. Right after I got tuned it was in the high 10s under WOT. This is the 2nd time this happened. Got tuned 1 year ago and it started running lean shortly after. Thought it was because the fuel temp sensor went bad but now with a new one and no CEL it’s doing it again. Also it sputters/misfires sometimes after I shift. Any ideas? 2005 MR on E85, FIC 1000cc high Z injectors, walbro 255, and AEM wideband.

 

what your fuel pressure look like?
clogged filter?

 

Don’t have a fuel pressure gauge installed at the moment. Still using the stock sending unit with a brand new 255 and sock filter