2002 subaru WRX

A few months ago I bought a full AfterBurner 3” Decat turbo-back exhaust. I have been recently having exhaust rattles when engine is decelerating downhill or on start up and when hitting bumps. I looked under the car and noticed that the exhaust is hitting the rear driveshaft CV boot clamp. I have tried extended hangers but no luck. I tried pulling down the downpipe and rebolting but nothing. I returned the downpipe and got another but both fit the same. When I had the backbox and centre section fitted to the original downpipe there was no issues at all. Any ideas? This exhaust doesn’t have a donut gasket and is all flat flanges. It looks to me like the downpipe is pointing too far upwards? Will be under the car again tomorrow so give me any ideas to try!

Thanks

 

Have you the bracket on the gearbox.

 

Yes

 

Only fitment issues I've had is with cheap Chinese ones.