i jus bought a 98 trans am with a 383 stroker in it and its got a custom bult cam and i don kno the duration but i hooked it up to a scantool and its misfiring at idle but when i drive its fine b/c i culd tell if it was because it runs strong but the check engine lights on and i need to pass emissions and i thought it might be the TPS and was wondering what parts i shuld start throwin at it to fix the problem

 

Is it showing multiple random misfires at normal driving speeds?

If it's just happening at idle I'd suspect the computer calibration (tune).

Clean your MAF and IAC to see if that helps.

 

today i was drvin it and when i come to a stop and the rpms go down the car cuts out on me or itll drop to like 500 then go up to 1000 about 3 times then remain steady at 1000 rpm but after i give it gas it wants to die on my when the rpms go back to idle

 

 

agree with AL as it's probably something with the computer tune... but it couldn't hurt to pull/swap the plugs if they are kind of old, as their color tells alot

 

Depending on how big your cam is you're gonna have misfire codes. My car always has them.You can watch it misfire at idle. Thats the nature of the beast.
BTW good luck with the emission's!!!