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Old 11-27-2013, 10:50 AM   #1
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exhaust manifolds, what do I have?

This exhaust manifold is what was on my 99 2.5l when I purchased it. Are these stock? Is there normally a catalytic converter on these?


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Old 11-27-2013, 11:32 AM   #2
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The secondary "pre" catalytic converter didn't appear until 2000. That looks like a stock 97-99 manifold.

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Old 11-27-2013, 02:22 PM   #3
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aftermarket exhaust manifold

Would the aftermarket header exhaust manifold really make any improvement on power since this doesn't have the pre-cat?
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Old 11-27-2013, 02:33 PM   #4
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Quote:
Originally Posted by jdlmodelt View Post
Would the aftermarket header exhaust manifold really make any improvement on power since this doesn't have the pre-cat?
Small improvement at high rpm, probably noticable loss at low rpms.

If I had a 2.5 I would have stock manifolds ceramic coated inside & out to retain heat inside rather than dissipate that heat to the heads & camcover area.

May be able to gain some flow by grinding welds at tube entrances & exit also.
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Old 11-27-2013, 04:15 PM   #5
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No matter what you have for headers, those 400-600 cell cats are going to remain very restrictive.

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