Alright, I've got the sp2 catback and im not sure if other cat backs connect the same way but wtf is up with connecting two flat surfaces (the flanges) to each other and sandwiching a gasket in there. Do they do this to gaurantee that your gasket will blow out and cause a leak? Not to mention it makes for crappy fitment.

The area i'm having the most problem with is where the b pipe connects to the axle back. The original gasket that came with the catback was those foamy ones, which i expected to be crap...well it blew out and the exhaust sounded terrible. This sounds stupid, but i feel like it was the reason my car was starting hard and occasionally stalling when cold. Anyway, i put in this metal gasket i had laying around (nissan product) and it was a big difference but it was still leaking, i could feel the air coming out. I tightened these bolts down TIGHT, with my air tools too. So i went to autozone, picked up an exhaust gasket that looked like it'd fit...it did as far as the bolts and sh*t lining up. I turn the car on and its got a leak just as bad as the blown gasket. I dont know what to do. Honestly, i feel like chopping off the flanges and attaching that section with an exhaust coupler. Plenty of new exhaust systems attach using couplers and clamps...so why not greddy?

would it be stupid to sandwich the metal gasket and the other gasket in there together? i feel like its only leaking because the surfaces are not flat enough to sandwich the gasket in there, like the gasket is too thin.

another annoying thing about the flanges is they cause the b pipe to hang low because it can only bolt up in one position...which also, annoyingly puts alot of stress on the b pipe hangar causing them to break. ive got zip ties re-inforcing mine right now. I love the exhaust note and what not, but i've never been so frusterated f*cking around with something over and over and over. nothing else on the car needs this much attention.

 

Yes, you can double-up gaskets to help them seal.

You can also try using high temp "copper" RTV to make a seal. Just apply the gasket with a bead of this stuff, torque the bolts hand tight, and wait 12hrs. Then fully tighten.

Dave

 

hmm never heard of that sealant i'll look into it. but thanks! im gonna go try to double them up today and cross my fingers.

 

I would not use sealant. I have used 2-4 Nissan style gaskets without problems and I advise you to do the same.

 

2-4? the diameter of the hole in the gasket will be big enough though, right? 2.25? i'll go to nissan today and try to see what they got. chances are they have none in stock.

 

2.5in hole so no worries. I think advanced auto also carries the metal gaskets, maybe napa. Autozone has the "plate" gaskets.

 

sweet thanks. yeah autozone gaskets are crap

 

Permetex makes this whicked trick stuff called 'copper spray-a-gasket' "specially designed for sealing turbo-charger flanges, exhaust manifolds, blah blah blah, it fills in minor surface irregularities and also prevents seizng, sticking, and gauling of threaded surfaces, blah blah blah" The stuff works great, when used in addition to the nissan gaskets obviously.