I have a problem with my exhaust. It rattles during certain RPM's and I believe I know the problem. I believe there is a leak right where the b-pipe ends and the muffler begin. I just put a new muffler on and that didn't solve the problem that I thought it was. How would I go about fixing the leak? Any help would be appreciated.

 

Consider taking the car to a muffler shop and have them weld all the joints. I did the WSP Y / B pipes and muffler. After doing the install I had it all welded and it seemed to eliminate the noises. If this was just a bolt on OEM muffler it may be that you need a thicker gasket to stop any leakage. Be Safe, Mark V.

 

Is there supposed to be a gasket on the flang from the bpipe to the muffler? If there is I don't have one. Where could I get one for cheap?

 

You could go to Nissan and get the OEM copper multiplate gasket. Autozone might have a part that would interchange or you could just purchase some exhaust grade gasket material from them and make your own. If you don't have a gasket between a bolted together flange then the metal to metal contact will make some noise. Be Safe, Mark V.