Yeah, D is the worst. It effectively stops any meaningful debate, since it then places the speaker of it as the one who determines who is or is not capable of speaking on the issue being discussed.
If you need God goggles to understand something that says it is plainly written inside of it...
It could be the heat shield that covers the catalytic converter. They usually just tack weld them in place. I had the same thing happen with my Honda Civic, and finally just yanked it off (and was sure to only park where I wouldn't catch anything on fire).