Pre-cat Question?
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
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From: Denville NJ
Pre-cat Question?
Is there any down side to replacing the stock front "Y" with pre-cats with a catless one? Should I expect any trouble codes to be thrown. I assume that the 02 sensor has to remain intact. I'm also replacing the main cat with a high flow unit. Thanks for any help.
Safety Car
Joined: May 2003
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From: Vette-hid.com Lost in DFW texas
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St. Jude Donor '06-'07
Re: Pre-cat Question? (CG77VETTE)
I have had no pre cats for about six mos.I have never thown code I have a single car sound main cat.I even passed emissions visual and the sniffer.I bought my y-pipe off a guy on ebay.The same one midamerica sells.Search ebay.
Team Owner
Joined: Sep 2001
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From: Athens AL
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Re: Pre-cat Question? (CG77VETTE)
You should have no problems whatsoever, including emissions testing if you have them where you live, the main cat is sufficient to pass a sniffer test.
Its rare, but possible, to have problems with the O2, because it can read less heat in the exhaust. This is a problem Ive only heard of occuring with full headers, and not just a new Y, but its still very rare.
Its rare, but possible, to have problems with the O2, because it can read less heat in the exhaust. This is a problem Ive only heard of occuring with full headers, and not just a new Y, but its still very rare.
Instructor
Joined: Mar 2001
Posts: 230
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From: Phila. Pa.
Re: Pre-cat Question? (vader86)
Got rid of mine in my 86 a couple of years ago. Walker sells a package with their high flow main cat and a new front y pipe with no pre cats. Part no.15749. Cost $142.00 two years ago. Fit great. I'm not sure if that part number is a walker no. or the number my local parts house uses. That's what was on my sales slip. Good Luck. No codes ever tripped.
Pro
Joined: Aug 2000
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From: South River N.J.
Re: Pre-cat Question? (CG77VETTE)
I always wondered why those pre cats were there when you have a main cat. If and when I have to replace mine I was gonna go with a catless "Y" pipe, a random tech. high flow cat and a B&B cat back system. I think the main cat is all you need to pass Jersey emissions. I don't know if they could fail you on a visual for no pre cats though. Are the pre cats still available from the dealer. IF not then I don't think they could fail you on a visual. Let us know how you do on emissions.
