I have a 90gt 5spd I got about 8 months ago and it has always felt a little weak on the upper rpms almost like clutch slippage but never smelled clutch, more recently I'm thinking maybe it's something to do with the mass air meter setup on the car. It has a 70mm ford housing but what it came off of I don't know but the sensor on it is apparently an aftermarket replacement because there isn't any thing wrote on it but air flow and an arrow. So here's the part I can't figure out. I've tried putting a stock 55mm unit on it with 3 different F1ZF-12B79-AA AFH55-03B sensors. 2 of those sensors were questionable as far as whether they were good sensors or not. But 1of them was known good because I took it out of my mom's 93 tbird 5.0. Every F1ZFxxx...sensor makes the check engine light come on as soon as the motor starts and runs for about 2seconds. I pulled the computer to make sure it didn't have any tuning chips or anything plugged into the port on the back of it but it is still factory sealed so i don't know. Am I supposed to be using the E9Zxxxx numbered sensor? Any help or suggestions would be appreciated guys.