Whats the difference between our factory headers and aftermarket ones?

[#1GALANTFAN]

Does our car have stock headers? It sure does look like it. So what I wanna know is, what are the gains of getting headers (let's say RRE)? How are they different from the ones we got that'll help improve performance? I will eventually be buying these bad boys but I just wanna know if there is any difference, I just can't see how they would be better, I would understand if we had regular manifolds, but seeing as we don't, I just wanna know the difference.

[oakrdrs187]

Stock is just a regular manifold, the HP gains that come from an aftermarket header are because of the improved exhaust flow. Additionally some delete the pre-cat and main cat resulting in an increase in exhaust flow leaving a bad smell at the tailpipe and rasp.

[#1GALANTFAN]

I think the 4G69 engine does come with stock headers though, but thanks for answering where the performance gain comes from. Then I do have another question, because I don't wanna delete the main cat so my car can stay legal, is there a cat on the factory headers like around the collector? And if so, does the RRE headers remove that first cat? I don't care if that cat is off, because when they inspect my car, they only look on the pipe for the main cat, so I wouldn't mind if that first cat gets removed by the aftermarket headers, I just wanted to know. Thanks.

[johnygezony]

Nope, you still have a "manifold"

[#1GALANTFAN]

Ok, I'll take your word for it. But if you ever look at one it really does look like headers, I looked at them through the heat shield and there is each individual pipe welded to the block. And I still don't know the answer to my last question lol, I really wanna know.

[shartOFwar]

I think the 4G69 engine does come with stock headers though, but thanks for answering where the performance gain comes from. Then I do have another question, because I don't wanna delete the main cat so my car can stay legal, is there a cat on the factory headers like around the collector? And if so, does the RRE headers remove that first cat? I don't care if that cat is off, because when they inspect my car, they only look on the pipe for the main cat, so I wouldn't mind if that first cat gets removed by the aftermarket headers, I just wanted to know. Thanks.

Do you mean is there a cat on the main exhaust manifold? Yes there is. When you replace that manifold with the bolt-on RRE header is takes that whole piece out leaving you without the first catalytic converters

[#1GALANTFAN]

Yes, that's what I meant. Leaving a cat still on the pipe before the resonator but after the collector. Thank you, that's what I needed to know.