Pre Cat question
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 25
Likes: 0
From: Morgantown WV
Pre Cat question
I have an 01 Coup and am considering removing the media from the inside of the pre cats. Can anyone tell me if this mod provides any worthwhile gains? Any down side to doing this in a State with no emmission checks? Finally, can someone post the link to the Mike Murcury "how to" that discusses this mod.
Thanks
Thanks
Drifting
Joined: Oct 2002
Posts: 1,335
Likes: 76
From: Bedford Va.
Re: Pre Cat question (JayMullen)
i think the only documented gain was 4.5hp
i removed my pre-cats, its very easy.
remove the center section of the exhaust and the rear
o2 sensor wires. i used a long 1/2" drill to break up the cat.
pull the chunks out. you can lift the exhaust and tap it on end but not to
hard. now you need to remove the matting material that was around the cat.
i used a pry bar that had a hook shape on one end to scrap this material out.
i have also seen a wire brush on a long flex rod that you can put in a drill to clean the loose material out.
use a small mirror and verify that you have all of the matting out.
if not it will clog the remaining cats.
its very easy to get everything out, will not take long.
the pre-cats only clean up the exhaust at cold startup. after that they
are just back pressure.
i removed my pre-cats, its very easy.
remove the center section of the exhaust and the rear
o2 sensor wires. i used a long 1/2" drill to break up the cat.
pull the chunks out. you can lift the exhaust and tap it on end but not to
hard. now you need to remove the matting material that was around the cat.
i used a pry bar that had a hook shape on one end to scrap this material out.
i have also seen a wire brush on a long flex rod that you can put in a drill to clean the loose material out.
use a small mirror and verify that you have all of the matting out.
if not it will clog the remaining cats.
its very easy to get everything out, will not take long.
the pre-cats only clean up the exhaust at cold startup. after that they
are just back pressure.
Burning Brakes
Joined: Nov 2002
Posts: 862
Likes: 1
From: Cologne Germany
