oops, went to connect my new flexi unit to the Dedra's silencer, & its the wrong shape! The flexi unit has a triangular shape end & the silencer has a square end. It looks like the unit i bought is to be attached to a cat, but my Dedra is the non cat version! Any ideas.... I've already fitted the new flexi unit so a return isn't possible, am i stuck with a unit i can't use now?