Genuine Acura Legend Oxygen Sensor

Acura Legend Oxygen Sensor Parts Questions & Experts Answers

• Oxygen Sensor
  36531-PH7-305
  Q: How do you check and replace the oxygen, MAP, crank angle, throttle angle, and intake air temperature sensors on Acura Legend?

  A: To check the oxygen sensor, turn the ignition switch to OFF, remove the ALTERNATOR SENSE fuse for 10 seconds on all Legends or the HAZARD fuse in the main fusebox on Integra, and check the fuel pressure to ensure it meets specifications. If the fuel pressure is acceptable, warm the engine to normal operating temperature, block the rear wheels, set the parking brake, and raise the front of the vehicle securely on jackstands. Locate the oxygen sensor in the exhaust manifold, unplug the electrical connector, start the engine, and let it run for fifteen minutes at 1700 rpm without closing the throttle completely. Disconnect the wire harness from the oxygen sensor and raise the engine speed to 4000 rpm for about 10 seconds, then measure the voltage between the oxygen sensor side of the electrical connector and ground; it should be below 0.4 volts during closed throttle deceleration. Raise the engine speed to 4000 rpm again and measure the voltage, which should be above 0.6 volts during cruising rpm. If the results are incorrect, replace the oxygen sensor; if correct, have the wire harness checked at a dealer service department. For replacement, unplug the oxygen sensor electrical connector, unscrew the sensor, apply anti-seize compound to the threads of the new sensor, and install it into the exhaust manifold before plugging in the electrical connector. For the MAP sensor, check the vacuum hose for cracks and the electrical connector for a snug fit, replacing it if necessary. For Legend models and 1986-1987 Integra models, turn the ignition switch to OFF, remove the ALTERNATOR SENSE fuse for 10 seconds, warm the engine, and ensure the CHECK ENGINE light continues to flash. Disconnect the electrical connector from the MAP sensor, insert a test harness, and measure the voltage between the RED (+) terminal and the GAN (-) terminal, which should be about five volts, and between the WHITE (+) terminal and the GREEN (-) terminal, which should be about three volts. If the readings are okay, replace the MAP sensor; if not, have the circuit diagnosed by a dealer. For 1988-1989 Integra models, follow similar steps, ensuring to measure the correct terminals. For replacement, disconnect the electrical connector and vacuum hose, remove the bolts retaining the sensor, and install the new sensor in reverse order. The crank angle sensor consists of a CRANK/CYL sensor and a TDC sensor, with locations varying by model. For Legend models, check the CRANK circuit by measuring resistance between designated terminals and ensuring continuity to ground does not exist. If tests are incorrect, replace the sensor; if correct but issues persist, have the system checked at a dealership. For the CYL circuit, follow similar steps. Replacement involves removing the cruise control actuator, timing belt cover, and other components before installing the new sensor. For 1988-1989 Integra models, check resistance and continuity similarly, replacing the distributor if necessary. For 1986-1987 Integra models, measure resistance between specific terminals and replace the crank angle sensor if incorrect. For the throttle angle sensor, turn the ignition switch to OFF, remove the appropriate fuse, warm the engine, and check the CHECK ENGINE light. Disconnect the electrical connector, install a test harness, and measure voltage between terminals, replacing the sensor if readings are correct. For replacement, disconnect the electrical connector, remove the hold-down plate screws, and install the new sensor with a new gasket. For the intake air temperature sensor, measure resistance with an ohmmeter; if incorrect, replace the sensor, and if it checks out but issues persist, have the vehicle checked for ECU malfunction. For replacement, unplug the electrical connector, remove the screws retaining the sensor, and install the new sensor in reverse order.