I thought this was worth mentioning since I wasn’t able to find anything about it on the internet when I was researching it. Also, it should apply to XKs as well as our XFs.
Recently, my check engine light came on. I didn’t notice any symptoms of the car running differently, but the light stayed on even after restarts and cooling down. Using my scan tool, I found that my car had DTCs P0172 and P0175 which are both codes indicating “System too rich” (one is for Bank 1 and the other code is for Bank 2).
After checking quite a few things on the car involving the mass air flow sensor, TPS, oxygen sensors, and MAP, I decided to try removing both MAF sensors and cleaning them. Surprisingly, this did the trick and the DTCs haven’t come back since. I’m bringing this up because normally a dirty MAF will cause the opposite and result in a lean condition, but apparently not on our cars.
I know cleaning them will only be a short term solution, so I’ll be purchasing some new ones soon. Hopefully, this will be the last issue for a while. Its been exactly one year since I got my car, and thus far it hasn’t exactly been reliable. It hasn’t left me stranded or broke down, but I’ve dealt with several error messages that have popped up on the dash. Fingers crossed that my car just wanted some attention because it felt neglected by the previous owner and now realizes it has a sugardaddy for an owner.