I installed a used Yoshimura rs 3 exhaust (complete system). I am now getting a ticking noise somewhere in vicinity of cylinder 1 or 2. I also removed all the smog system. I have removed this system and reinstalled 3 times. I am using permatex copper sealant where upper pipe goes on by the flange, I cleaned the inner part of gasket in the head and everything else. This noise was not there with the stock exhaust. I'm about ready to just pull off and put stock exhaust back on any help in figuring this out would be greatly appreciated. I also used a mechanical stethoscope and a hose held in my ear to try and figure out which cylinder is causing the noise and cannot figure it out.