I went to my old work (muffler shop) and checked my back pressure. It was 9 psi before the cats- way too much! once it gets to 5 psi you should look into replacing your cats and finding out why they went bad in the first place.

My car only has 75k miles on it.. just giving you guys a heads up, you might want to have yours checked. (Your local muffler shop should do it for free) all you have to do is drill a little hole in the pipe and put a pressure gauge in.

 

I don't have cats! o/r FTW!!!! What part of texas?

 

What kills cats besides sulfur? They don't wear out from doing their actual job right, like a rich mixture won't burn them out? Or do they usually clog as opposed to burning off the catalyst?

 

doing there job will eventually wear the cats out. A rich mixture will just accelerate the process.

 

Yep, replaced cats twice on my 280K Ranger, they just wear out!

 

This is a good link explaining why cats fail, there a bounch of other good info on the rest of the site too.

 

Cats can fail from overheating plain and simple. It melts the metal mesh inside. This could be from unburnt fuel going into the cats and burning(too rich)

Northwest Houston

 

I have Magnaflow cats, do those die quicker than stockers?

 

not sure.. but when I worked at the shop no one ever came in with a magnaflow cat that had gone bad

 

my cars been runnin rich for about three months so mine are probly clogged right?