i tried changing the fuses but that didnt help.
based on your description , towards the middle of your car located is your catalytic converter so it could be just the cover of your catalytic converter thats making the noises. still you need to go underneath your car and make sure that it's not about to fall while your driving.
Well, you are going to have to get the guy to show you, because until I remembered about unions, I created a couple of plumbing nighmares in my house where I could put it together but not take it apart. Under the conditions you claim, not fully threaded. I thought for a moment that you could make a distorted frame and catch only a few threads as it was flattened, but that would not meet my definition of rigid.
