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: 6,520
Likes: 1,306
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: 6,520
Likes: 1,306
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.
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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!
