2004 Corvette hatchback low mileage. Recently had my H-pipe and axelback upgraded, also Dyno'd.

Well, the next day afterwards, I started getting a slight, random rattling kind of sound from the back, passenger side. I thought it might be the new exhaust loose or bumping around. Brought it back to the mechanic, looked at it, and no problems. They suggested maybe be the bushings so they sprayed some penetrating oil on them.

The idea is that this vehicle has probably sat a lot in the last 4 years (only 10,000 miles), and that being up on the lift for the exhaust work might have shaken the suspension somewhat. Anyway, still can't identify the cause of this random noise. Any ideas?

 

My 2 cents....your catalytic converter needs to be replaced.