Sorry for the delay in replying, my pc decided it did not want to play anymore!!Mind me asking why you think it has gone
Thanks for that, I will take your advice and have the codes read.i really think that guessing at the O2 sensor is wasting money - at least have the codes read! the O2 sensor is not used during or immediately after cold start, so is not going to make a difference to this particular problem, sorry.
I will print off the instructions for the upper one later this evening,, please remind me so that I find the post again