Hi Gary, the most likely cause is the exhaust knocking the bar; they don't always end up in exactly the same position, (different exhaust manufactures and different fitters). Grab hold off the exhaust (don't forget they get hot) and give it a good hard shake, if that's the problem you can usually bend the fittings to move it, also bear in mind an exhaust grows in length when its hot, so it may not foul when its cold. On the other hand if the tow bar is loose or the detachable part is not locking tight this is far more serious and would need looking at by someone more qualified to do so (no offence intended). If its been fitted recently I'd take it back anyway.
Facebook
Twitter