Need advice, 00 s10 Blazer: No power at WOT, starts hammering noise under hood at around 2000 rpm, will not up shift out of 1st gear when floored from stop until letting up on throttle. RPMs go up and down slightly while driving normal holding steady speed around 20- 40 mph. Setting obd code 404. Discovered I'm not getting 12 +v dc to the red wire on terminal E of the 5 pin connector plugged in to the EGR valve , neg. lead of volt meter grounded to neg. battery post, pos lead probed in to red wire of term. E at EGR valve, ignition in on position ,not running. But if I unplug the connector from the EGR valve and test, I then get the +12vdc, plug connector back in voltage disappears . I took the vehicle for a test drive with the EGR valve unbolted and just hanging. It had great power, shifted from 1-2 at WOT, no banging under hood, no surge at cruise speed, It ran ok except it would stall at stops if you let off the throttle. Why would I have voltage with EGR connector unplugged and not with it plugged in? Would appreciate any advice. Thank You.