i just put on a dc sports 4-1 header and it leaks at the test pipe so i went to schucks and bought 2 of these lead o ring gasket things how do these go in?

 

you have to take the header out, and if its the gasket that im thinking about, then it should look like a doughnut. look at where the header meets the cat and there you will see a similar gasket, pull or pry it off of the header and put the new one on. pretty simple, and you only need one. also be on the lookout for warping if you bought a two piece ceramic header, where the manifold meets the downpipe.