Originally Posted by Lonewolf4858
Backfire through the intake, ignition timing, backfire through exhaust, valve timing. The other thing could be a restricted exhaust. You can try disconnecting the exhaust pipe either at the manifold or before it goes through the cat and then try driving it.
Just need to pull out the pre cat o2 sensor for that test.
To the OP, do you get a dummy light?? Check the codes with the on-off switch thing....sometimes a code is stored on the pcm but the CEL is not lit.