no catalytic converters

[noid]

Considering i never have to pass emissions again in my area. Thinking of replacing my cats with some straight pipes. Any one have some video's of e30's with no cats? How loud is it? Worth doing? Disadvantages?

[DCColegrove]

No good reason to dump the cats.

[Jesse30]

Avoid the noid!

[Scotaku]

No good reason to dump the cats.

Tell that to Carter Hunt. :(

[blunttech]

no gain and stinky exhaust . leave it as is. my stock m20 sounded marginally louder without a cat and not necessarily better. it stunk too

[TheDos]

I don't have a cat on my car (no emissions in SC). Its a little louder, but not too bad and the exhaust note isn't as clean of a sound. Besides that, there is really not all that of a noticeable difference.

[dlmpsy]

If your cat isn't bad, no reason to eliminate it. I gained +2mpg with no cat. The exhaust sounds louder, as far as smell goes, a bad cat smells like rotten eggs, I haven't sniffed my exhaust lately so I don't know how it smells.

[der affe]

i seemed to get better mileage without the cat, by 3-4 MPG's. the downside was it was too loud for me (the aftermarket cat had gutted itself). i cut it out and replaced it with a pair of smooth bore glass packs. the sound was way nicer, except it buzzed every time i lifted the throttle, that got really annoying.

i am going to use a turbo muffler as a resonator this time. that should quiet it down and not buzz

[T Verdier]

my car smokes a little more, its raspy, and it smells like an old junky truck. I dont mind these isuess but i will have to get a cat when i want to get it smoged.

[TwistyTunedE30]

the m30 enjoys no cat as far as i can tell by the seat of the pants dyno however it went from oem exhaust to no cat 2.5"...it does smell like anchovy fart though and if you have any kind of a light colored car be sure that it will leave a nice carbon mark on it within a minute of running it lol...however im in sleeper mode so it doesnt matter. Just get a higher flow cat, headers, and a turbo muffler and youll be better off than just hacking the cat to pieces.

[DCColegrove]

A properly functioning cat will actually help extract exhaust and causes no restriction to speak of.