The check engine light comes on when the weather dips below -7 degrees celcius (or so). Usually when I hook it up to a diagnositc machine, I get one of the following codes: P0171 or P0174.
Today while driving to work, the light came on again. I hooked up the scan tool, and it came back with NO codes. The light was on, but no codes were present? How is that possible?
My O2 sensors seems to be working fine according to the scan tool (the graphs are not just flat, there is some movement), so what else could be causing the problme? Specifically, what could be causing those codes? Why does this only happen in the cold weather?
Wednesday, January 6th, 2021 AT 2:16 PM