Removing pre-cats, problem?
Thread Starter
Melting Slicks
Joined: Aug 2001
Posts: 2,753
Likes: 1
From: Fishkill NY
Removing pre-cats, problem?
I plan on getting a new front "Y" pipe with no pre-cats and a new main cat. Will I get any error codes? I'm not sure but, I think the O2 sensor is on the pre-cat right? If so, will I need to do to fix the error code? :(
Thread Starter
Melting Slicks
Joined: Aug 2001
Posts: 2,753
Likes: 1
From: Fishkill NY
Re: Removing pre-cats, problem? (AS84)
Does anyone know if 91's have the O2 sensor in the same place as the 90. The DynoMax "Y" pipe I want to get comes with a new main cat, not sure if it has an O2 sensor mount but, its for a 1986-1991 so it must.
Also, I think there is a small tubing that connects to the pre-cat on the pass side, right? Not sure but if there is, what do I do with that?
[Modified by 1991C4, 11:03 PM 1/5/2002]
Also, I think there is a small tubing that connects to the pre-cat on the pass side, right? Not sure but if there is, what do I do with that?
I removed mine and no codes appeared! The sensor is located just above the drivers cat on my 90.
[Modified by 1991C4, 11:03 PM 1/5/2002]
Le Mans Master
Joined: May 1999
Posts: 6,517
Likes: 1,304
From: Windermere FL
Re: Removing pre-cats, problem? (1991C4)
Not sure if the 91 is exactly the same as my 90 but the one I got from MAD was a direct bolt on. No codes or other problems. O2 bung was in the exact same spot. I replaced the O2 sensor just to make the job easier :yesnod: Nice mod. Might want to consider going all out with true duals and headers :D, and skip the front Y-pipe all together :smash:
Thread Starter
Melting Slicks
Joined: Aug 2001
Posts: 2,753
Likes: 1
From: Fishkill NY
Re: Removing pre-cats, problem? (Flame Red)
I have been the header route in the past and putting them in is a real pain in the $#*&. Plus, as you can see in my SIG, I have allot of money invested in the side pipes and I dont think they support true duals :nono: What did you pay for the "Y" pipe from MAD? I can get a "Y" pipe and a new main cat for $250..
Le Mans Master
Joined: May 1999
Posts: 6,517
Likes: 1,304
From: Windermere FL
Re: Removing pre-cats, problem? (1991C4)
As I recall the SS front Y pipe was about $200 from MAD. I did replace the main cat, which was another $100 from Discount Auto. (also a waste since some how it later mysteriously got gutted by some big irate iron pipe and hammer)
$250 sounds like a deal to me!
$250 sounds like a deal to me!
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Removing pre-cats, problem? (1991C4)
That tube comes down from the AIR diverter valve and goes into the main cat. It should have a hose clamp holding it to a prong on the right side exhaust manifold at the Y-pipe flange.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Melting Slicks
Joined: Aug 2001
Posts: 2,753
Likes: 1
From: Fishkill NY
Re: Removing pre-cats, problem? (Flame Red)
Thanks for all the info guys!! The "Y" pipe combo I can get for $250, I'm not sure if its SS, its on page 81 of the Ecklers #2101 catalog. You think I should go with SS? I never drive it in bad weather and its allways in the garage.
As I recall the SS front Y pipe was about $200 from MAD. $250 sounds like a deal to me!
