2003 GMC Yukon Denali XL Base 8 Cyl 6.0L
2003 GMC Denali XL Check engine light Codes PO174 And PO171 Bank 1 and 2 too lean?? What part do I need to replace?
It's your MAF, mass air flow sensor. If this sensor craps out or gets dirty it will trigger one or all of the oxygen sensors to spit this code out. Look in your vehicle manual and figure out where the MAF is and you can clean it yourself with a little brake cleaning fluid. If you have the money, i'd go ahead and just buy a new one to be safe. This isn't a serious problem, just an annoying one because it will cause the sensors to keep tripping out.