Well after I brought from ebay a cat replacement pipe for the car it was sitting in the front room (not a good idea) so today I started to put it on the car, there are a total of 7 nuts to remove to get the front part of the exhaust off the car, all but one was simple to release (ok, some needed a little heat and persuasion) but the last one, could not be moved, I tried all items penetrating spray, heat, and even brought a nut splitter but this also failed (actually broke the tool).
Whilst searching on the net I spotted a mobile mechanic, gave him a call and 2 hours later he was here, took him longer to take off his helmet than removing the nut. Literally 5 minute job, its easy when you have the correct tools.
So after that, another 1 hours work from me to put on the new pipe, and start it up, its defiantly louder now. We will have to wait till next weekend though to see how it runs.