Hey,
I have a 2018 XC90 and the engine light turned on. The vehicle feels as it wants to turn off at times. I’m getting code P0172 System too rich. Looking to replace the mass air flow sensor. Has anyone gone thru this process? Any advise would be greatly appreciated.
Thank you.

 

generally when you have a fuel trim issue, the first thing to do is to check for intake air leaks which may be allowing unmetered air into the system. Have you done a realtime scan to see what the fuel trim is doing during the drive cycle (ie are you running rich at idle or at speed etc?) You can also remove the MAF to inspect the intake tubing - say to see if its dirty or oily. While its open you can try cleaning the MAF with a product like CRC MAF Cleaner (don't use carb cleaner as its solvents may be too harsh for the grid in the MAF). You can also inspect or listen for exhaust leaks which may mess up the O2 sensor's readings