DTC P2A00: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1) Or DTC P2A03: A/F Sensor Circuit Slow Response (Bank 2 Sensor 1): Notes

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: This DTC may be caused by the vehicle running out of fuel.

NOTE: DTC P2A00 or P2A03 may be also detected when the air fuel ratio is stuck rich or lean. A low A/F sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich. A high A/F sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.

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