Dazed and Confused
Join Date: May 2012
Location: Upstate New York
Re: 2003 4.6 intake manifold gasket
I answered you before., but I didn't see anything about a misfire. Either the manifold or the gasket is leaking. You can get it pressure tested to see if you can see where it's coming from. Another way is to wipe it down as best you can, then give it a light dusting of talc and see if you can pick up where the leak is originating.
Ever notice that there's so many high performance parts available for GM products?
Did you ever think that maybe they NEED them?