Depends on the quality of the shop......

even the best silicone is only good up to 500F so it will fail eventualy on manifolds and cats that can reach temps well above that.

Doesn't matter. No ones gonna pay 3 hours additional labor for a TP job.

RTV copper is 700*. It never failed me on a 1600* turbo, but I use a gasket with RTV on both sides.

That's what I've seen on the back of every tube I've ever bought. Every time I followed directions it worked flawlessly. The only time RTV didn't work for me was when I was using it to redneck-engineer something and it was the wrong tool for the job.

My high temp copper rtv gaskets are working, but I wouldn't mind adding those z1 gaskets to my wishlist :) Thx for the idea

No they don't. The cat flandges are offset and the pipe physically sticks into the header. I'll upload a pic later today but when I took my cats off. No gasket

http://i.imgur.com/9IQIwYeh.jpg

Didn't you buy used? Looks like someone modded your car before haha. Looks like a crush gasket to me on that. But what do you think 9 and 18 are?

Yeah, that pic shows a metal gasket squished around the pipe.

Here's the 09 PDF, same as the 13 pic above, gasket at every location.

I have been using the COPPER as others have said the COPPER RTV for years. Both mating surfaces must be clean, real clean. Place a good sized bead on the TP flange, then tighten it up, but not torqued down. I let it sit for an hour, then torque it down, done. NO leaks long after gaskets start leaking. 8 bucks at advance for a tube enough to do a whole exhaust.

OK so there is a metal crush gasket that only fits on the cat. There isn't anything like the pic you posted on there. I bought my car used but it was bone stock down to the air filter.

This is a donut style gasket. If you want a leak-proof design, this is the route to go. Unfortunately, I can only think of one company that makes aftermarket test pipes where the piping protrudes the flange to allow this type of gasket to be used, Motordyne ART pipes (newer version).

I've used RTV sealant by itself, with gaskets, I've tried Z1 metal gaskets (which are still on the car). They all have leaked on me, on the passenger side where the manifold bolts to the upper flange on the test pipe. This is on two different sets of aftermarket test pipes - as I thought it could be the way the pipes were produced and not allowing them to sit flat on the flanges to bolt down, causing them to leak.

The Z1 metal gaskets held up the best and the only way to actually tell it's leaking is by listening through a stethoscope, pretty minor. You can't see much black soot around the flanges as you could with the other gaskets and just using RTV sealant, so from the naked eye it looks fine.

I finally got a hold of a set of newer ART pipes that will go on the car once the weather gets warmer.

Now its bone stock, wasn't before. :tup:

Sounds like an over tightening problem. Without cheating and looking, tell me the torque spec? I bet you bent the header flange. You'll need a straight edge and you'll have to check the surface of it. In the manual for example it says the header flange to the head is out of spec if there is like 0.028" gap.

http://www.nicoclub.com/FSM/370Z/Coupe/2013/EM.pdf. Page 41 and 145

That's what I thought too until I ran the stock cats after the fact without any problems / leaks whatsoever.

However, thinking about it, it would be pretty hard to bend the flange if you're using just a socket wrench and not an air impact wrench. Plus it wasn't gorilla torqued whatsoever.