Originally Posted by 2003LariatCustom
Cleaned my MAF but my check engine light remains illuminated, any ideas on the probable cause? codes of both P0174 and P0171 are what i was given in the diagnostics.
Check for a collapsed CCV hose on the rear of the intake / throttle body. It goes from the PCV on the passengers side valve cover to the top rear of the intake, just barely under the cowl at the firewall.
Mine was showing the same codes and I first cleaned the MAF, only to later discover it was a collapsed hose. Amazon sells that hose (OEM Spec - Ford part) for about $25.