Have you replaced the plug wires lately? Mine started doing that and it was a plugged catalytic converter. I drilled out the honeycomb on the pre cat and replaced the plugs and plug wires. It ran fine for a while then started missing and backfiring and it came up with a misfire code. I replaced the coil pack and it is running great now.
I also did some modification on the O2 sensor so it would not throw a code and that seems to be working. I bought two used coil packs on line for $32 including shipping so now I have a spare.

Last edited by homerdog; 05/01/08 01:23 AM.