Vehicle: 2003 Toyota RAV4,
2WD, 2.0L, Automatic Transmission
Problem: The vehicle came from another shop.
They had installed a new Mass Airflow (MAF) sensor but the
MIL/DTC would not clear.
Details: The technician pulled DTC P0171.
The fuel trims verified that the fuel system was lean. The
technician introduced propane into the intake manifold. The
Oxygen sensors and fuel trims responded correctly.
Confirmed Repair: Since the fuel management
system appeared to be working correctly, the technician decided
to replace the aftermarket MAF sensor with an OEM (Denso) MAF
sensor. He cleared the Keep Alive Memory and performed the
appropriate dive cycle to insure the repair was complete. The MIL
did not come back on. Problem solved by an OEM part.