Magma

So I'm new to the LS scene just bought '99 Trans Am w/ 70,000 miles. 5.7 V8 yada yada yada... After letting it warm up I hit it super hard and heard a rattling noise coming from the driver's side. Seems near the engine. Also slightly different exhaust tone. Welp that's it. Help is appreciated

ss.slp.ls1

iTrader: (36)

Can you elaborate? Are you driving or reving the engine while stationary, and is there a difference between the two scenarios?

Magma

It's only while driving, nothing out of the ordinary while reving.

Mart00SS

iTrader: (19)

Im going out on a limb but when the factory motor mounts get worn they allow the engine to move a significant amount when under a heavy load. The Y pipe could be coming in contact with the floor pan of the car. Online diag is super hard but hope this helps.

AnotherWs6

iTrader: (17)

Ping? OP are you aware of what detonation sounds like? My stock car would detonate pretty badly on a hot day when I bought it.

ChopperDoc

Heat shield near the exhaust maybe? There isn't much room for the exhaust down there. My interior rattles pretty good when driving around. It's just old. A lot of things could cause this type of sound.

Like said already, it's tough to diagnose on the interwebs.