Toyota 89465-39835 Oxygen Sensor

The coolant temperature sensor on four-cylinder engines is located on the rear of the cylinder head, while on the 3.0L V6 engine, it is found on the intake manifold beneath the air intake plenum at the rear, and on the 3.4L V6 engine, it is positioned behind the timing belt cover on the top of the intake manifold. Before installing a new sensor, wrap the threads with Teflon sealing tape to prevent leakage and corrosion. To remove the sensor, release the locking tab, unplug the electrical connector, and carefully unscrew it, taking care not to damage the sensor as it affects the fuel injection system. Install the new sensor quickly to minimize coolant loss and check the coolant level afterward. The Mass Airflow Sensor (MAF) is located on the air intake duct and measures the mass of air entering the engine; to replace it, disconnect the electrical connector, remove the air cleaner assembly, and lift the MAF sensor assembly from the air cleaner. The vane airflow sensor, found on 1993 and 1994 3.0L V6 engines, measures the volume of air entering the engine and is removed similarly. The Intake Air Temperature (IAT) sensor is located inside the air cleaner housing and is removed by unplugging the electrical connector and twisting it out of the rubber boot. Oxygen sensors, which monitor the oxygen content of exhaust gases, are located in the exhaust manifold or pipe; precautions include avoiding damage to the pigtail and ensuring air circulation to the sensor. Disconnect the battery before removing the oxygen sensor, and use anti-seize compound on the threads during installation. The Throttle Position Sensor (TPS) measures the throttle valve position and is located on the throttle body; it is removed by disconnecting the electrical connector and unscrewing it. The crankshaft position sensor is mounted in the timing cover for four-cylinder engines and on the oil pump for 3.4L V6 models, while the camshaft position sensor is located above the intake manifold for four-cylinder models and behind the timing belt cover for 3.4L V6 models. Knock sensors, located below the intake manifold, control spark knock by retarding ignition timing and require coolant drainage for access. The Vehicle Speed Sensor (VSS) is found at the rear of the transmission housing and sends a voltage signal to the ECM. Lastly, the EGR gas temperature sensor, mounted near the EGA valve, detects exhaust temperature and regulates EGA on/off time efficiently.

A new sensor is pre-coated with thread sealant; do not apply additional sealant. Install the knock sensor and tighten it securely (approximately 14 ft-lbs), then plug in the electrical connector, refill the cooling system, and check for leaks.