if your car is leaning you should probably check the suspension.
but really, how did you determine the car was lean? wideband or narrowband o2? was it detonating? if you had your 42s at 100% and its still not getting enough fuel with just a jrsc bbk then you may want to check fuel rail pressure. yes fuel filter or pump could be the culprit if pressure is low.
but really, how did you determine the car was lean? wideband or narrowband o2? was it detonating? if you had your 42s at 100% and its still not getting enough fuel with just a jrsc bbk then you may want to check fuel rail pressure. yes fuel filter or pump could be the culprit if pressure is low.