Things to do or check... 1, The Heads Crack on the right hand side (nearest distributor) check yours isnt cracked! 2, Did you use a new gasket? 3, A Thin Smear of Exhaust Paste is a wise move to help seal... 4, Loctite any nuts and bolts is a wise move! Stops them coming loose! I Myself have had to do this on my ct9 setup! 5, Check for cracks on welds of the manifold (Black Exhaust Sutt will be visible)