figured it out. #3 fuel injector is shot. unhooked its power and the car runs as normal as it can (on 3 cylinders that is) no back-firing, no studdering, no stalling, relatively normal. just out of curiosity, does anybody happen to know if the injectors out of a b18a are the same as the b18b? just in case i end up goin to a junkyard for this thing, which i probably will because a new injector is gonna run me $104 from advanced auto.