Thanks Tony and Darren,

I will be very annoyed if I find that the "genuine" Bosch MAF I fitted is not what I was promised. For a few squid extra, I now find that I could have gone to main dealers and know that I have the genuine article. The relevation that the cancellation of the fault code could have automatically reset the settings is interesting. The moment I pressed the cancel button, the engine note changed and I got the lean readings. The engine was hot at the time and assuming the MAF was genuine then I have to seriously consider the 02 sensor. There was no switching of sensor at fast idle and no air leaks found. Will query MAF suppliers before I spend any more of the old boys money.

Regards

Pete M