Took the cat section off this weekend, bit of a mare due to access and noticed bolts securing were pretty loose, someone else must have had similar probs I expect. Cat section and flexi were all good but found hole in middle exhaust section whilst moving cat which hadn't been obvious beforehand. Pipe joint to silencer was flexing. At least I have found it so will use gunn gum for now and try and replace middle section next week. Got extension bars but didn't suit connectors but managed to source 3/8th to 1/2" whilst in B&Q, surprisingly good value motoring section in there.