Just fitted a straight through centre section to my 06 wrx the middle part of the pipe has a wider circumfrance and is dead tight against the underside of thebody and bangs against it when driving.
Wondered if anyone else has had this problem, looks like it will only go on one way aswell,can they be fitted the wrong way?
Thanks in advance.

 

Yes, someone on the Surrey Scoobies forum had a similar problem. I think they made some adjustments to it to stop it knocking. I think the tools they used included a large hammer.