There are three different gaskets you need to replace or atleast consider replacing when changing out the exhaust manifold. First is the exhaust manifold gasket which is where the header connects to the head (btw make sure to use factory torque specs when reinstalling). Another is the gasket where the downpipe connects with the catalytic convertor and the one I'm worried about is the gasket that sits in the middle between the downpipe and the top part. The stock gasket is actually two little donuts that sit in an indentation on the down pipe and are wedged between the two (very efficient) the other which you find on most cheap ebay headers is a flat metal gasket which if you do not torque the 3 bolts right will leak like crazy (also you can't find it at autozone). If its name brand like dc sport, etc.. you shouldnt have a problem finding all the gaskets at any auto store.