BMW 320d SE
Help! I had my cat replaced by Renault last week, and now the pipe between the cat and the spilt into the two backboxes is knocking into the mount, resulting in a nasty resonating sound at high revs, and when changing down. It's actually the steel hanger on the pipe hitting the bolt that holds the rubber hanger onto the car. I've enclosed a piccy to clarify. It's a blueflane exhaust. Any ideas on how to solve this? Thanks.