i have the headers and soon will be prdering the y-pipe what will i need to connect the y-pipe to my stock cat

 

You wont really be able to keep you cat in the stock location, You will be able to cut the stock cat-back to fit, will have to either have it welded into place or have the cut end flared and clamped over the y pipes outlet,I would have it welded into place.

 

i dont really want to keep the cat but my car will be shipped back from germany so it has togo through cudtoms

 

If you have to pass emissions before you go to Germany then I would wait with the install. Because you won't pass them anyways. You'd need to have SMOG legal headers to pass emissions. Unless you know someone on the inside. If I were you I'd just wait with that install.

 

no got to have them to come back from germany