96 Buick Century with P1406 code (and occasional P0300/P1406 Pendings)

Hi Cig,
Yup, I looked over the site and it’ll be easy enough for me to follow. Just need to figure out which box my DMM made it into, as I’m getting ready to move. Or just go and pick up a new one. Thanks for the suggestion, I’ll give you an update when I make it through the testing process and figure out if I just bought a bad EGR valve or if there’s some other issue in the loop somewhere.