I’ve been driving an ‘05 Matrix/Vibe for over five years now (well maintained by an older family member, and kept in storage for its first 12 or 13 winters), and winter after winter it’s the exact same story…

Temp goes below freezing, CEL pops on within a week, firing a coin flip between P0171 and P0172 fuel system codes. When the temp rises above 40°, the CEL will disappear after a little bit of driving.

The first few winters I owned it, it pretty much lived in the shop for this problem. Replacing the oxygen sensor…only for the light to come back. Replacing the MAF sensor…only for the light to come back. Replacing the oxygen sensor again…and on and on and on.

It has never caused noticeable problems with the car’s function, but if there is a problem causing this no one has ever found or solved it. And at this point I don’t take it in when those codes are all I get, since the light always comes back until springtime hits and it’s gone again. I do check it, just in case the system finally fires a different code this time but…five years on, those two codes are the only two it’s ever fired.

Any other Matrix/Vibe drivers have issues like this with their CEL? Is this just a feature of a ~20 year old system? Could its early life in winter storage have impacted the fuel system’s ability to manage in cold weather? Is there some hidden issue a half dozen mechanics over the years have missed?