Quote Originally Posted by Turbo4door View Post
Rotten egg smell means the cat is working, but the engine is running pig rich. Usually smells like that when you floor it multiple times. You must fix your misfire issue before you go wasting money on a downpipe to continue having the exact same problems. Just sayin...
his misfire can be due to a clogged cat.... thats the first thing i would fix. then get plugs wires.