hi i have a problem my 325is is acting up i really think is because of fuel yerterday night i really needed fuel and there was no good gas stations around so went to a cheap one used 91 but still the car feel like S**t what can i do? car has chip,288 cam,longtube headers conected to SP exhaust,s4.10,19lbs injectors,stage 2 clutch,027 AMF,huge cone, thats what i can think of right now.. but i have never had any problem with it can some one help me?????:(