This morning I went under the dash and pulled off all the tape, removed the switch, and taped all the wires that were involved and now the check engine light is out.
I thought about taking it back and accusing the dealer of trying to cheat the smog laws (check engine light on = no pass smog...
I just bought a used 06 Duramax, 2500HD crewcab, about a week ago. Two days ago I found a red switch under the dash that was added by the previous owner (bought it from a dealer so I did not meet them) so I flipped it and the check engine light comes on, but I can't tell if anything else...