If it's the cat, your even-side head is at great risk. Fix it quick before that head cracks on you.

 

I am having these same problems with my truck and it's driving me crazy because no shop within miles of here can figure it out. Like they say all possibilities have been ruled out or replaced. The cat is hollowed out, the plugs are good, the wires are good, the distributor is good, fuel pressure is good, no MAF sensor code. Just an O2 sensor code that has been up for years since it has a loud after market muffler. I am stumped to the bone. The problem is my truck will run fine for days and then misfire like crazy. The newest problem is it shooting fire ***** out of the muffler. HELP!!! That truck is ready to get parted out since no one around here can figure it out after 2 months. Thanks

 

How many miles on your truck? Have you investigated the plenum yet? Done a compression test? How old are the tuneup parts? When mine pulled this stunt, it was just a severely carboned up dist cap.

 

It has 135,000. A mechanic friend went through a compression test and checked the plenum. Tuneup parts have about 5000 miles on them. Everyone seems to be stumped as to why it dosen't constantly misfire and only sometimes. Thanks

 

Start checking electrical connections. Coil, injectors, PCM. Also grounds. Two up by the power steering pump, and I think there is another on the back side of the passenger head.

What did the compression numbers look like?

Where in SE michigan are you?

 

The DodgeForum is not a dating site.

Thank you.

 

Dammit VW, you spoil all my fun.

 

I would have to check with my friend to get the numbers. I checked every darn connection in that compartment! I'm in Pontiac.

 

I think I would revisit checking the plenum..... has it ever been repaired?

Do you get random misfire? Or, is it specific cylinders consistently?

 

Sounds like maybe the muffler is clogged with debris from gutting the cat that may not have been all removed. Disconnect the exhaust after the cat and see if there is any difference.