Does the rear gasket (closest to the muffler) re-use the stock muffler donut and hardware or a regular aftermarket gasket? I have tried even double stacking gaskets and still have a pretty decent exhaust leak. Any help before I get back under the car would be awesome.

 

Pretty sure you would just use a vibrant exhaust gasket. I wouldnt think you re use the donut one. If you still have trouble they do sell some gaskets that are a little bit thicker.

 

Are you sure you have the donut facing the right way? Rounded part into the pipe, flat edge against the midpipe.

 

I haven't tried the stock donut yet as the Greddy kit did come with a standard 2 bolt crush gasket (3"). I did double stack them as the gap between flanges was awful. I'm trying not to resort to hi-temp goop and the standard gasket if possible. The way the flange on the greddy is stamped ( BTW i think this is poor engineering for them ) and the conical shape of the interior of the pipe It looks like it should be donut style in 3". I pick up a Walker 3" ID donut tomorrow and will report back .

Thoughts on this greddy system: Greddy RS

Poor design. Bad flanges ( stamped not CNC), reduced pipe size near cat ( though they fixed this with the most recent offering), hangar has a end cap tack welded on and of course this already popped off when handling before install. No hardware for silencer ( though I won't use it ). I have had several exhausts ( APEXI GT spec, Greddy PE, HKS Ti, Tanabe) over the years for my supra and never had any of these critiques or problem. Poor showing Greddy for the EVO.

 

Maybe you just got a bad one have to called Greddy and talked to them about the problem?

 

No and your right I should call them. I did buy this 4 years ago and it has been sitting in box

 

I have Greddy as well and my story with this issue, I had used just a regular gasket ( not donut ) with just regular non OE bolt and nut, which same thing had a leak.. I had tightened it as much as I could without stripping or breaking stuff and was still a slight leak which frustrated me but was going to deal with it at a later time. I checked it after driving it a while went to check and the leak was no longer there. not sure if the heat settled the gasket or what. You could try the same but if not talk to Greddy and see what they say the recommend fix is.

 

I have ti-c and I had same issue, but it is becasue the the bolt hole area was bent by previous owner. (I got this for free... can't complain. )
But I don't think it is hard to seal though.
I just stack up 3 gaskets and it sealed very well, you do have to man torque it though.

and you dont reuse donut ring.

 

I dunno man when I put an aftermarket on my old Subaru I had similar issues then realized I still had to use the stock donut in the middle and all was well. Gaskets won't do it alone I went down that road too once before.

 

I'm picking up the 3" donut tonight, but in the mean time stacked 3x2bolt gaskets and it seems to work without leaks. I'll update on the donut if its a viable option.

 

Well if the stacked gaskets is working why mess with it!