DTC P0171, DTC P0172, DTC P0174 Or DTC P0175: System Too Lean/Rich: Notes

WARNING: This page is about a different car, the 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: These DTCs may be caused by the vehicle running out of fuel.

CAUTION: If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

NOTE: DTC P0171 and DTC P0172 apply to bank No. 1. DTC P0174 and DTC P0175 apply to bank No. 2. Heated A/F sensors are located on each exhaust manifold. Heated A/F sensor on rear (firewall side) exhaust manifold may also be referred to as bank No. 1 sensor No. 1. Heated A/F sensor on front (radiator side) exhaust manifold may also be referred to as bank No. 2 sensor No. 1. A/F sensors may also be referred to as A/F ratio sensors.