Harry Truman once said, “If you can’t take the heat, stay out of the kitchen.” He could have been talking about either thin-skinned politicians or header gaskets. It’s hard to imagine a component that ...

is it a donut joint, or flat flanges? if they're flat, then there should have been a gasket of some sort there. And no, foil and tape isn't going to cut it. Exhaust gaskets are typically metallic.