I am talking about ring between Y-pipe to End muffler

I forgot to bring the ring to the shop, so they installed stock exhaust without
the ring. Does it affect anything?

I hope I do not have to go to the shop again

 

The gasket is there to prevent exhaust leaks. Drive for a week and see if there are any sooty, black marks around the flanges. If so then you have a leak.

 

^ Thanks, so it does not affect any performance or sound right?..I will check if it leaks

 

If you have a leak it could cause a sound problem. Sometimes a hiss, sometimes a tick.

Even if it doesn't make noise, it probably would be a good idea to run a gasket.

 

There was hiss sound when I bought the car. Around 1.5~2k rpm.
I will drive this week and do something. I hope the shop does not charge more than $20..
Or I can just do DIY..Oh I check the muffler and then I think the shop put used gasket in the back section instead of ring.

 

Most shops will have gaskets in stock hanging on the wall. I'm sure they put one back in it.

 

I can't belive that any good exhaust shop would put it together without SOME KIND of gasket. Just call them.