Well the up pipe where it attatches to the turbo has a 3 bolt donut style gasket that came on the car from the factory. That is usually all that you need to make the seal. Sometimes it will leak from behind that gasket though so poston enterprises sells a copper 3 bolt gasket. Their website is Welcome to Poston Buick ! If you are missing that factory gasket though you will need to find someone that has one to replace it.