LS1 Exhaust noise

[4-2 Camaro SS]

So I heard a weird kind of odd noise yesterday. I have a 1998 SS convertible M6 with 42,500 original miles. It does not have any SLP options (It is the single exhaust version) I was driving down the road top down and I heard this weird air noise. So I pull over into a parking lot and realize it's coming from my car. It seems to be coming from the rear by the tip/muffler. It sounds like air is pissin out of a tire but it doesn't sound or feel like a hole in the exhaust. I went to drive it later that day and didn't hear it until the engine had warmed up to around 190 deg. It is pretty loud and annoying lol. I may jus be lookin for an excuse to get a loudmouth system or something but I have never heard this noise before. Any tips?????

[94 formula]

Is there any chance it was more of a humming than a hissing noise? If so that could have been your fuel pump.

[4-2 Camaro SS]

no because that's what my dad checked firtst and it's more around the whole rear end of the car. My gas mileage has gone from 18.5 to 16 and that is rather unusual. It sounds as it's coming from the muffler. My car gives a lot of heat off from the bottom of the car.

[DierDesire824]

?SS has single exhaust muffler / pipe i thought they had dual at the back ?//// the less i cant help you with diagnosing but im sure someone here has a better idea

[toddwirges]

EGR problems?

An exhaust leak wouldn't kill your mileage. It might, however, occur only when the car is warm (metal expansion rates).

I'd try stuffing a rag in the exhaust pipe to try and find any leaks. I think the most common place from the factory are where the intermediate pipe goes into the muffler, and at the cat joint up front.

The single exits actually flow pretty well. On a vert the SLP muffler system would probably be pretty nice and quiet enough.

I have a LM2 on my vert and it's a little too noisy imho.