L98 Catalitic Converter
Thread Starter
Racer
Joined: Jun 2004
Posts: 313
Likes: 0
From: Macomb MI
L98 Catalitic Converter
This will be a spring project, but I am looking for some help. Took my L98, 91 Coupe, (87K) to a local Chevy dealer in November, due to some hesitation at various speeds. Had them check to see if it needed a tune-up, broken plug wire, etc. They told me that the Catalitic Converter needed replacement. This is where the story gets better.
They could not replace it because of the side pipes and they did not have a lift to raise it.
Some questions. Anyone know if the L98 has pre-converters. I have trouble getting under the car any more but from what I can tell it has pipes coming down. Next, I have a neighbor that owns used car dealership who suggests that I have a guy that does work for him gut the converter and run a straight pipe thru it.
Anyone have any thoughts? Thanks!
They could not replace it because of the side pipes and they did not have a lift to raise it.
Some questions. Anyone know if the L98 has pre-converters. I have trouble getting under the car any more but from what I can tell it has pipes coming down. Next, I have a neighbor that owns used car dealership who suggests that I have a guy that does work for him gut the converter and run a straight pipe thru it.
Anyone have any thoughts? Thanks!
Advanced
Joined: Jan 2008
Posts: 75
Likes: 0
From: hinton ia
Well I'm not sure about the 91's but my 90 had 2 pre-cats one just off each bank and one true cat after they collected. I cut all three out and put two new cats in place of the pre-cats runs great. but other than the legal issues i dont know why you couldn't just rip them off and weld some straight pipe threw them.
Drifting
Joined: Aug 2002
Posts: 1,775
Likes: 125
From: Birmingham AL
Yes, it has 2 precats and 1 main converter. I would reccomend using a 49 state legal y-pipe with no precats and a new high flow converter as a direct bolt in replacement as long as you are not in CA.
Burning Brakes
Joined: Feb 2008
Posts: 988
Likes: 7
From: Sarasota Fl
The '91 came with 2 pre-cats before the main cat. Don't forget that the main cat has a fitting to be attached to the AIR pump system via tubing. If you have side pipes, you may not have a stock set-up though with the stock front y-pipe. You'll have to get under to see. And take it to an exhaust/muffler shop for this - it'll be cheaper than a stealership if you're outsourcing the work. They will be more experienced in removing the cat, expanding tubing, etc. Post back here with a price estimate before getting the work done too.And yes, you can gut the cats. Whether you'll have enough back-pressure then and if it'll pass a sniffer test is a different story. The noise level will increase some too with new cats or a gutted cat. It will also be ILLEGAL in all 50 states....Doesn't stop people from doing it though.
Last edited by janarvae; Jan 6, 2009 at 01:54 AM.
