Beg your pardon Chris my mistake, It is 0.7 -0.8 volts not millivolts. Yes I've tried activating the EGR and scoping the feedback sensor at the same time, I can't see anything wrong, and watched it operate under under ECU control as well, I scoped the AMM and watched the O2 sensor the AMM peaked at about 4.3v and the O2 sensor was 0.8v for most of the acceleration period. Fuel trims are Ok, it's got me stumped. I think the next step it to have the ECU tested.

Mark