I've got a 2001 Buick Regal (3.8L/Auto, 144,000 miles) in the shop with a hard P1404 code. (The following data was taken with a Genisys, so scantool data names may vary)

EGR Learned minimum volts is 0.41. Reported/actual Pos volts is 0.81v. (Which equates to... Login to read more.