You have got to be kiddingAdi at Weymouth is a first-rate choice for any work on RVs. But, as you live in Kent, you could try Mercury RV in Teynham nr Sittingbourne. Not everybody likes him on this forum and so this post will probably be taken down soon. It's just practicality.
DontHi again, and thank you all, so much for your comments, and advice. 7 MPG? my God!... I suspect that mine, (also a 7.4 Ltr) probaly does around this, as I can actualy see the fuel gauge, go down, when driving. Am having the the "LPG" serviced soon, which means that it will do even less MPG, on "Gas" but being cheaper, will compensate, I hope that then, I will get around the equivalent of 12 MPG, of the Petrol.
Forgive me, but what does "OBD2" stand for? Thanks again, what a helpful site, (And People) this is, so glad I joined. Will contact "Mercury RV".