[Beav]

I've been at the same impasse Harvey. The only thing I can lay my feeble mind onto is a lean backfire but that doesn't allow for the overheating exhaust. Either late timing, excessive fuel or a plugged cat/muff does that. I was hanging my hat on an ECT with transitional/intermediary dropoff. I'm still not sold that it isn't. An overheating electrical part would continue to worsen, which isn't happening and I hate condemning an ECU without solid validation. I only had brief access to the database and I hate pushing the issue since I was sneaking in. I would expect that an intake backfire could dislodge hoses or even split them and cause erroneous MAF data, for that matter the MAF may also have suffered damage. You're right, most MAFs are bad across the range, save for some Mits and the old Bosch hotwire MAFs (BTW - what is it with Europeans and electrics anyway? Bosch, Marelli and, my all time fav, Lucas, aka 'The Duke of Darkness'.) I think the best bet is some time spent with a GMM, a vacuum gauge, a fuel pressure gauge and maybe a gas analyzer - nothing like a live datastream.