PeachParts Mercedes-Benz Forum - View Single Post

400Eric · #2 08-05-2010, 08:34 AM

Yes, one or more cats may be plugged or plugging.

Don't eliminate the cats unless you are sure you'll be able to get away with it. Don't just "gut" them either. It's been proven that some back pressure is created by allowing the exhaust gasses into an open chamber and then forcing them back into a pipe again. The best way to do it is to run a straight pipe through the cat after gutting it by breaking up all the contents into pieces small enough to exit out each end. A plus of doing it this way is that you only have welding beads at each end of the cat instead of on it which makes it less suspicious looking. Welds on each end just look like the welds you would normally have when the cat was welded in place. (We have visual inspections out here.) Since the cats won't be making heat anymore, you won't need the heat shields but I'd leave them in place for the same "maintaining a stock look" reasons.

I don't think the wire type is important. I have two different friends who use coat hanger wire when they do exhaust system work.

You didn't say which car this is but eliminating the cats may cause O2 sensor issues since the pre-cat cats are often upstream of that sensor. On 96 and later cars (and some older ones) that will cause the C.E.L. to come on. Many folks here have cars that are not in their sigs, myself included. I'm curious, which car is this?
Regards, Eric