I've gone through the same thing but it's hopeless. The pipes rust out from the inside from the moisture that condenses in there. The best way to make the pipes last is long enough trips on the highway to get those pipes nice and hot.

Answered by caradiodoc (expert)
17,308 answers provided

That's good to know! Would the paint hurt or affect the cat or muffler negatively?

Answered by Joeboldt
0 questions asked

In the good old days, mufflers had a small drain hole at the back of each muffler, i still run a 1/8 drill through to help drain off water after short trips, been doing it for 45 years, but the steel used to day is just so thin its just rubbish.

Answered by mhpautos (expert)
26,913 answers provided

You don't want to get paint or rustproofing on an oxygen sensor. They measure the oxygen in the exhaust system by comparing it to the oxygen in the atmosphere. You don't want to block that tiny opening between the wires. Also be aware oxygen sensors don't work until they get to 600 degrees. Any paint on the catalytic converter is just going to burn off. You'll need engine paint to withstand the high temperatures the pipes will get up to.

Answered by caradiodoc (expert)
17,308 answers provided