Contour Enthusiasts Group Archives Forums Modifications Duratec Performance MSDS Headers....

O-k...this weekend I'm installing my MSDS headers. My question concerns the stock SVT catalytic convertor. I've seen posts that indicates its not much of a restriction...and others that indicates it is. General consensus seems to be that gutting the main cat is a no-no. Can I get some educated views here? Any one with dyno data?

Thanks in advance...

So if you leave the main cat on you can still pass emissions? I have always heard that the headers will make you fail emissions. Shed some light.

People out in Kalifornia have (from what I've heard) passed emissions just fine without the precats. IIRC I've even heard people passing without ANY cats, but the car must be warmed up first. I'm not sure how true the latter one is. I plan on only running the main cat when the time comes.....

Originally posted by whitegt:

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So if you leave the main cat on you can still pass emissions? I have always heard that the headers will make you fail emissions. Shed some light.

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i've sorta heard the same...that at least one person has passed with gutted precats...u'll certainly pass visual...i 'think' as long as the main cat is in good shape it should be cool

actually if the mechanic actually knows Contiques, you would NOT pass visual with the headers, as there is no pre-cats. If you have gutted manifolds, and they don't see where you drilled the front manifold (if you did) then you would pass.

Just a lil clarifaction

Originally posted by gdub520:

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i've sorta heard the same...that at least one person has passed with gutted precats...u'll certainly pass visual...i 'think' as long as the main cat is in good shape it should be cool

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Fellas...I'm in MI..and could care less at this point about passing emmisions! Come on Demon...Stazi...all you pros...I need some advice here? I'm not looking to add a big HP gainer only to lose some of the stock cat is a big bottle neck. But the flange at the end of the Y is huge...and a normal 2.5" exhaust flange will not work.

Help?

Get a good aftermarket high flow main cat. The SVT unit sucks.

I can get you a CarSound (makers of Magnaflow) cat from my distributor if you want. It is a high flow unit.

But get a hold of me ASAP, I am heading to Kalamazo this afternoon so I could bring it with me.

In any case yo don't want headers and no cat cos the rasp is HORRIBLE without a main cat.

email me anastazi.sarigiannis@aam.com