Do you have the stock H-pipe on the car with cats, the Cats have covers and if 1 or more of the weld is shot it makes that sound. I riped the ones off that ratteld on my car. only take the ones on the road side OFF, or just get a new H-pipe
And yes it could be the muffer too Jack The car up and look and hear it, Make sure the Car will not move if it is started. Good luck!
------------------
Engine: steel mounts, Under drive pulleys, K&N, Home ported Lower Intake, No power steering, No A/C
Drive Train: 3.55, T-5z,
Real power STUFF I Have and will put some time: Mac cold intake, 70MM TB, Valve covers (COOL ONES)255 Fuel pump NOS Dry 75HP, AFR 165 58cc, GT-40 Intake.
Next to get: Rocker Arms,Cam,Injectors 24, What might I need???See It at
www.computerconquest.com