check engine light came on the other day and it's finally warmed up enough, meaning double digits, for me to pull the codes. I got a P0150 and a P0174. A quick check show both to be connected to the front heated O2 sensor. It also said that possible bad wires could set a code. Is the sensor mentioned the one right in front of the fan shroud? If so, I think my may have been replaced at an earlier date with a non OEM one as the wires bend at a hard 90 degree angle coming out of the sensor and are against the shroud. I can see no visible breaks but that doesn't mean much. So the question is, how hard is it to pull the shroud/fan out? There isn't enough room to get a slotted socket between the shroud and the sensor to replace it otherwise. I just hope whoever replaced it last was smart enough to use anti-seize.