well it dnt think i have a leak in the exhause sustem but yes i installed the boost fooler which is just a lil conector with a wire run across it but my truck has a knock to it and if you shoot the exhause manifold with a temp gun the #1 cylinder is over 100 degrees cooler than the rest of them i thought it might be a valve

 

Eaither a valve seat or a bad injectors! Been there done that. DDP makes a great injector thats TESTED before it leaves

 

well thanks 4 the advice i think its a valve seat