CATALYTIC CONVERTER

[yao500e]

You'll see some moderate (perhaps 5HP) gain if you remove the cat, just due to decreased restriction in the system. And you can and should only remove the cat if you legally can do this (i.e. your local or state government doesn't require it). You also may gain a bit of resonance/noise with removal of the cat.

There are alternatives such as "high-flow" cats that provide less restriction than the stock cat does, while still giving you the emissions reduction that is often needed.

That said, I'd only remove the catalytic converter if it's not required, and also as part of an overall exhaust system redesign to reduce total exhaust system restriction. Just removing the cat and replacing it with a "straight pipe" is really not going to get you much, in and of itself. Work with an exhaust shop to design an entire exhaust system from the exhaust manifolds back to the tailpipe.

Cheers,
Gerry

I assume after 30+ years, i assume catalytics can go bad and perhaps even clogged a bit? changing to new 200 cell catalytic would help?

 

[TerryA]

@yao500e,
Don’t assume the CATs are bad after 30+ years. Look at Glen’s high miler w/625+K miles on it. It still passes CA Smog with good numbers. My own 93 500E passed CA Smog with flying colors.

If a car has been properly maintained the CATs should last a very long time. I’m not saying CATs don’t go bad but probably most would from impact damage or using bad fuel or engine issues that dump to much raw fuel into the exhaust system.

Below is my latest CA Smog Certificate. You can find one of Glen’s high miler on his Owner’s Thread.

lol

 

[gsxr]

Terry is right. Factory cats can still function perfectly after 30+ years and a half-million miles.

 

[yao500e]

@yao500e,
Don’t assume the CATs are bad after 30+ years. Look at Glen’s high miler w/625+K miles on it. It still passes CA Smog with good numbers. My own 93 500E passed CA Smog with flying colors.

If a car has been properly maintained the CATs should last a very long time. I’m not saying CATs don’t go bad but probably most would from impact damage or using bad fuel or engine issues that dump to much raw fuel into the exhaust system.

Below is my latest CA Smog Certificate. You can find one of Glen’s high miler on his Owner’s Thread.

lol

Hello @TerryA Got it! thank you. awesome. then the cats on my e500 and C36 should be fine.
Now the next question, does a 100 cell or 200 cell help with air flow and any HP gains?

 

[yao500e]

Terry is right. Factory cats can still function perfectly after 30+ years and a half-million miles.

perfect. thanks.

 

[TerryA]

Now the next question, does a 100 cell or 200 cell help with air flow and any HP gains?

@yao500e,
Check w/@szvook, He is the only one I know that has High Output CATs. They were very expensive $$$$. They are part of his totally custom exhaust system. He may have some info on HP/TQ gains if there is any. If nothing else I think he has one of the best sounding exhausts on a 500E.

PM him I’m sure he could answer your question.

Good Luck