everythings fine, plugs wires new engine and opti, starts up fine even replaced the battery. when im at a stop light and its warmed up it will rev up and down and will die if i dont give it some gas. when im driving along it feels fine and if i give it a little gas it feels fine, but when i let off the gas to come to a light or turn it will sputter out and die, sometimes i can keep it idling in park or neutral but sometimes i cant, any ideas here?

 

Idle Air Control (IAC) could be dirty or malfunctioning or the harness that drives it.

 

Some scan data on IAC counts would be helpful.

Make sure your intake elbow is on properly.

Also post basic info on the year of car, mods, etc. (the signature is a good place for that)