A heads-up for anyone considering a Dynomax cat..

I bought a Dynomax cat about one month ago at a local exhaust shop, and had it installed with 2 1/2" tubing from the stock downpipe to the stock GSL-SE muffler. This was in preparation for other planned mods: RB header, presilencer, and muffler.. yeah, baby!

All was well for about two weeks (no backfiring), but for the last two weeks the backfiring has gotten more and more frequent. It's the same symptom my stock cat had, when it finally went bad. And there's also a strong smell of sulfur (rotten eggs) that's really getting my attention.

I'm thinking of going back to a STOCK cat..

 

Rotary exhaust is a lot hotter than that of a piston engine. I've read that a normal cat could get destroyed pretty quickly.

 

when u put a non-rotary cat (something other than the factory or the mazdatrix) u have to disconnect the air-pump to get some life out of it or it will burn in no time.