I know the stock exhaust has this and I've seen some aftermarket with and some without. Is there a function of this other than the obvious flex feature?

Any help is greatly appreciated.

Thank you
Phill

 

so when your exhauts shakes side to side, the welds dont crack on the exhuast.

 

They ALL should have it somehow. It's to allow the engine to move around with the flexibility of the engine mounts. Sometimes one (or more) joints in the exhaust have a cone-shaped donut gasket that acts like a ball & socket. That's the case on my '95 Integra, right before the catalyst & also at the rear axle.

 

all of the above and it reduces resonated vibration from the exhaust system