I'm about to replace my stock cats with HFCs.
Do I need new gaskets where the cats attach to the headers and the Y pipe, or do I just use the old ones?

 

For the header-cat gaskets, just reuse the OEM Nissan gaskets. They are "metallic".

Usually, aftermarket HFC will come with their own gaskets for the HFC/Y-pipe side (iirc, 2 bolt gasket).

Do you have the stock exhaust? The OEM gaskets look pretty good.

.

 

my HFCs are used and didn't come with gaskets...?

 

I will replace them to new. It's only few bucks at local muffler shop.

 

Id replace for $12 to not worry again.

 

You just want to use new gasket incase of any leaks

 

The OEM gaskets are totally reusible, I've had mine off and on several times
with 4 different systems....Or if you need to spend the $ drop by Nissan
parts counter and get a new set. (cheaper than Infiniti)
Gary

 

Exactly. If you happen to have all of the necessary OEM gaskets (2 bolt & 3 bolt gaskets), then definately reuse them.

If you happen to other aftermarket gaskets already in place, chances are, they are already cooked.

.

 

thanks for the input guys..

 

so they are the same exhaust gaskets? i went to nissan today to get stock exhaust gaskets and they said that they didn't know if they were the same as the infinitis

 

re-use the OEM that are on there.

 

+3

The stock gaskets are the best. Much better than the aftermarket gaskets typically supplied with test pipes or cats.

I've reused mine probably about 50X with all the development testing I've done.

Still no leaks.

 

I can't... they are gone. I need new ones cause i might be getting rid of the g and need new gaskets for the stock exhaust. i'm currently running hks

 

if you have a dealer near you, you can picked them up from the parts dept.

 

will the 350z gaskets work