Powertrain - Faulty A/F Sensor Causes DTC's

Faulty A/F Sensor Can Cause Multiple DTCs

A faulty A/F sensor in a 03-05 MDX or '04-05 TL can cause any or all of these DTCs to set:

^ DTC P0134 [rear A/F sensor (bank 1, sensor 1) heater system malfunction]

^ DTC P0154 [front A/F sensor (bank 2, sensor 1) heater system malfunction]

^ DTC P2237 [rear A/F sensor (bank 1, sensor 1) IP line high voltage]

^ DTC P2240 [front A/F sensor (bank 2, sensor 1) IP line high voltage]

To fix this problem, check the sensor wiring and connections for damage. If the sensor circuit is OK, and the DTC(s) come back afier clearing them and doing a short test-drive, replace the A/F sensor. The replacement A/F sensors in Honda parts stock are an improved version over the original sensor.