Cutted cat.. does it throw a code?
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
Re: Cutted cat.. does it throw a code? (two-tone86)
no codes set on mine, it's been almost a year. That is if my assumption is correct that a "cutted cat" is the same thing as a "gutted cat" :jester :jester
[Modified by TA, 10:21 PM 9/13/2001]
[Modified by TA, 10:21 PM 9/13/2001]
Burning Brakes
Joined: Apr 2000
Posts: 959
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From: Lemoore CA
Re: Cutted cat.. does it throw a code? (two-tone86)
Shouldnt throw a code, but mine does throw a code 32 intermintently because of lack of Back pressure I believe.... I wouldnt worry about it though, if you either leave the precats and/or leave the exhaust tube connected to the cat youll be fine.
Paul
Paul
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From: Fort Worth Texas
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Cruise-In I-II-III Veteran
Re: Cutted cat.. does it throw a code? (two-tone86)
on an '86 I doubt that it would throw a code. I've heard that for some reason 1990 and 1991 cars are more sensitive and will throw a code.
Intermediate
Joined: Sep 2001
Posts: 49
Likes: 0
From: Belleair FL
Re: Cutted cat.. does it throw a code? (89 Paul in cal)
Codes wont be visual until 97 on (i think). C4s with post cat sensors (OBD II) will issue a code, but will not illuminate the SES... Those vehicles that do not use post cat sensors will not set codes.
The critical question is will the issuance of a fault code affect performance? Yes and no, depends on year according to different sources. I do know that the C4 OBD IIs will not adjust fuel trims based upon discreps between pre and post cat sensors... Pre/Post cat discrep may result in poor touring performance on newer vettes from others I have spoken to, but WOT will not be affected. Pre/Post cat discrep on OBD IIs should not result in either poor touring or WOT performance...
The 89 is not an OBD II PCM so you shouldnt see any issues I would think.
The critical question is will the issuance of a fault code affect performance? Yes and no, depends on year according to different sources. I do know that the C4 OBD IIs will not adjust fuel trims based upon discreps between pre and post cat sensors... Pre/Post cat discrep may result in poor touring performance on newer vettes from others I have spoken to, but WOT will not be affected. Pre/Post cat discrep on OBD IIs should not result in either poor touring or WOT performance...
The 89 is not an OBD II PCM so you shouldnt see any issues I would think.
Intermediate
Joined: Sep 2001
Posts: 49
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From: Belleair FL
Re: Cutted cat.. does it throw a code? (Stratocaster)
Hey, dont gut the cat unless it is already damaged. Gutting cats gain you mid range performance, but if you are familiar with Bermouli (sp?) equations for fluids, going from a particular diameter to a larger one, then back to the particular diameter creates turbulence. You never attain the higher RPM performance that you would think you should. Gutting a cat would never equal that if you just replaced the cat with a test pipe of like diameter of the rest of the exhaust.
People do see better performance for gutting a cat, but a test pipe performs better. and when you get down to it, swapping out a test pipe for the cat during inspection just assures that you pass both the visual and sniffer tests.
People do see better performance for gutting a cat, but a test pipe performs better. and when you get down to it, swapping out a test pipe for the cat during inspection just assures that you pass both the visual and sniffer tests.
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Safety Car
Joined: Jul 2001
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From: Pinellas Florida Misfit
Cruise-In III Veteran
Re: Cutted cat.. does it throw a code? (Stratocaster)
Don't have to worry about any inspections here... I would most likely be using a test pipe.
If I decide to keep my car, I'm thinking of removing all the cats and using a power effects system on the rear. Hopefully I can find an exhaust shop here in the Tampa FL area that will bolt a converter on ,but leave it very loose so I can swap it out with a test pipe. Of course, replacing the front Y may not be worth it at the moment if I'm considering building the engine and need headers.
If I decide to keep my car, I'm thinking of removing all the cats and using a power effects system on the rear. Hopefully I can find an exhaust shop here in the Tampa FL area that will bolt a converter on ,but leave it very loose so I can swap it out with a test pipe. Of course, replacing the front Y may not be worth it at the moment if I'm considering building the engine and need headers.
