Noob here so please be gentile. I recently purchased a 94 f150 regular cab, longbed 4x4 with the 5.0 and auto trans. The truck has 192k miles on it and the engine was replaced by a previous owner at 172k. When driving the truck from inside the cab I am hearing a loud ticking noise from the engine compartment that gets louder as the engine revs. Thinking it was an exhaust leak I crawled over and under to see if i could see any obvious signs of a leak. I did find that it appears the catalytic converter was replaced at some point, with one that does not accommodate the tube coming down from thermactor system. In fact the down tube appears to be missing entirely, with just the rubber hose coming off the air diverter valve. My question is could this be loud enough to be causing the noise, and if so can i just plug the hose with no ill effect on the system? I would love to remove the system entirely, however where I live in Pennsylvania they still do emissions testing.

 

Cat tech has gotten to the point to not need cooling air. I take all mine off, but I'm PA emissions exempt.

Adrianspeeder