Removing the cat...

[unclejemima]

My 91 beat is due for a exhaust change...and I would like to remove the CAT if possible. I've heard that as long as it is pre-92, then it is ok to do without causing any problems. Is there any think to worry about, like the ECU throwing a code if the Cat is gone? Just curious if anyone has done this yet?

I would get a "manifold to Cat" and then a new "Cat, back exhaust", but I doubt you can even buy the "manifold to Cat" any more, plus it probably cost near a fortune!

Thanks,
-mark

[Steve_M]

Its not wise to remove the cat.

The Oxygen sensor require a certain amount of back pressure to be able to meassure the fuel ratio, with no cat very little back pressure will cause poor fueling, most likely weak mixture which can cause detonation and valves to burn out due to increased combustion temperatures.

Its also possible you will actually loose power rather than gain any, if thats what your thinking by removing the Cat.

[unclejemima]

Its not wise to remove the cat.

The Oxygen sensor require a certain amount of back pressure to be able to meassure the fuel ratio, with no cat very little back pressure will cause poor fueling, most likely weak mixture which can cause detonation and valves to burn out due to increased combustion temperatures.

Its also possible you will actually loose power rather than gain any, if thats what your thinking by removing the Cat.

Very good reply, as always Steve!
The only reason I was hoping to remove it because I would like to replace the COMPLETE exhaust system, and I was wondering if the manifold to cat exhaust piece was very expensive? Are there other ones, or just OEM Honda avail? I then plan on getting a nice catback unit from Japan.
I figured that something would not work right if I pulled it out. Good to know. She's staying in and I'll save up for a new one! Its just that it is 18'ish years old, and it may be getting clogged up???

[beardo]

What about getting a sports cat built into the new system?

[TADO]

i've been oggling at these recently:
http://www.rsmach.com/_src/sc296/Catalyst1.jpg
at the moment i've still got the standard cat with a stainless manifold and cat-back. my friend from japan is coming over next week... i wonder how much one weighs?
uncle-j - have you seen the options here before?
http://www.rsmach.com/beat/a_category/index.html
and:
http://www.pro-service.jp/cgi-bin/pr...ge1&category=1

[Mylee]

http://www.pro-service.jp/cgi-bin/pr...ge1&category=1

Some quality goodies there......

[unclejemima]

i've been oggling at these recently:
http://www.rsmach.com/_src/sc296/Catalyst1.jpg
http://www.rsmach.com/beat/a_category/index.html
and:
http://w ww.pro-service.jp/cgi-bin/p...ge1&category=1

Cool! I was unaware that such goodies were available! I hope to afford something like this in the summer!
Thanks again for the links!

[Adam]

Hey I removed the cat a few years back and the car didn't drive any better infact I went back and put the cat back in.

I wouldn't recommend it.

[unclejemima]

Hey I removed the cat a few years back and the car didn't drive any better infact I went back and put the cat back in.

I wouldn't recommend it.

Cool, thanks for the advice! I will leave mine in!
Take care,