oem exhaust
 

Just a quick question. Is there any difference between a s4 and an s5 exhaust? How about between an s5 n/a and an s5 turbo?

I recently removed the exhaust from my vert project and discovered a tear in the metal where the exhaust pipe connects to the muffler. This car has never run under my possesion yet. So I dont know if the cat is still good or not. Its got surface rust but not bad other than the tear.

I found a new exhaust online, used. Has 5 hours of use. Owner didn't like the sound, decided to go aftermarket. What would be a good price for this? Would you guys rather have someone weld the tear. Or jump on this exhaust deal. Anything I should look for when I go to check it out? Thx guys!

The turbo exhaust is set up the same for s4 and s5...you have a pre-cat/downpipe, then an extension pipe, then the main cat, then the catback.

The NA exhaust is set up slightly differently for s4 and s5. S4 has two precats that go between the header and main cat, from there back it is the same as the turbo. s5 has a short extension pipe coming off the header instead of the first precat, but then you have the same precat in the #2 position and from there back it is the same.

The s4 cars tend to have "round" shaped mufflers while the s5 cars tend to have "oval" shaped mufflers that are slightly larger. As far as I know there is no performance difference between any of the main cats or catbacks.

Most of the precats are badly clogged or have already broken into pieces or are gutted.

Most of the main cats have already been gutted too. But, sometimes you do find unmolested main cats still intact. If you have a main cat that you intend to use, you need to pry off the heat shielding gently at the corners, then examine the corners of the cat body itself, they tend to crack and split open and form a huge exhaust leak. So the corners of the main cat always need welded back together, but you can't see this until you remove the heat shielding. It can be replaced after the welding repair is done.

It's usually not worth welding onto muffler inlets, if you have a crack already then the thing is most likely thin as paper due to rust and there's not enough metal to weld to. You just have to replace the whole muffler or catback.

If you are looking for a OEM replacement type cat back exhaust, this is what the Mazda dealership installed on the car for the previous owner, when the factory parts rusted out - Davico Ultra Fit brand:

86 91 Mazda RX7 Dual Muffler Exhaust System All Models | eBay

Nice and quite plus it fit fairly well.

Ty you guys so much