Thanks again for the info Guys. I've run over the ecu earths all ok apart from pin 78, but no wire to this pin. I've checked again the feed for the earth to the MAF & Lambda. The orange wire coming from pin 36 on the ECU carrys 11.45v at idle. Is this pin number correct for the floating earth to these sensors. I'm thinking this is looking more & more like an ECU fault?