The heat shield on the Catalytic is making noise when the motor is cold. It's almost like a buzzing noise. Most of the noise goes away once the motor warms up to temp. The bolts seem tight. Any suggestions before I go back under?

 

So you can put pressure on it and make it stop ?

Maybe bend the heatshield away from whatever it is touching ?

 

check for small rocks stuck between the cat and the shield itself.

if the shields themselves are pusted and rotting...for a cheap quick fix buy some large hose clamps and wrap teh whole cat/shield assy to tighten everything up

 

mine did the same thing a while after the header install. They drilled a few new holes and screwed it in, but after a while it came back. So what i just had them take it off. I never got any sounds or heat from taking it off. Even a few techs at the dealer said it would be fine to get rid of it.

 

Thanks for the suggestions guys. I'll give it a try over the weekend and worse case, they come off.