Amateur mechanic question here. Be kind. Replaced my existing pipes with factory replacements. When I put the new pipes on, I noticed that at the block, pipe is slightly loose even though cap nuts are torqued properly, and the pipe has a slight leak when engine is running. Looking at an online schematic, I see there is a gasket, part number 1106A in addition to the 2 piece collar, part 92152. Thing is, when I took it apart I don't recall seeing a gasket, so not sure if it is still there stuck to block or disintegrated. It did not leak prior to my putting the new pipes on. Do I have to go back to the dealer and hope this is a generic part they have in stock, or worse, order and wait a week or more while its on backorder? Any other suggestions? Thanks!