I went to Checker auto and had my codes read because my "service engine light is on". My car runs good but when in reverse or pressing on the gas and going really slow (like through a drive through) it kind of chugs. I got 3 codes
1. P1640 - QDM 1 - Failure
2. P1670 - QDM 4 - Failure
3. P1406 - EGR Valve Pintle Position Circuit
Does anyone know what a QDM is??
I thinking of replacing my EGR Valve but its $155 and how knows if it will fix it...