'93 Z28. ok ... i have the air temperature sensor removed and i think that is my main problem with the sputtering, but its only just now beginning. my Trans-Am air temperature sensor was messed up, and since i never drive my '93 i swapped the '93 sensor into the TA. so, thats the reason for not having a sensor in the '93. so, after the car is at normal operating temps, it sputters through all gears. like its not getting any air. i have a high idle (around 1700-2000rpms) and was told by a good friend/mechanic that my vacuum hoses may need replacing since i've already replaced the IAC sensor. so could the vacuum hoses have a hand in the sputtering as well? Its not an Opti promblem, already changed that and the sputtering never occured until i removed the sensor. i may be answering my own question here, but i was just curious if anyone else has had a smiliar problem?