Toyota 89465-60150 Oxygen Sensor

When you are dealing with an oxygen sensor or an air/fuel ratio sensor, the pigtails that are permanently attached to it cannot be unplugged; once the electrical connectors are broken off or pulled off, the sensor is considered unusable. These connectors, the louvered end of the sensor, and any mating surfaces should remain free of grease, dirt and other contaminants, and reagents such as cleaning solvents should not be used on these sensors. One has to be careful not to put too much pressure on the sensors or drop them, and if the sensors use a silicone boot, it has to be fitted appropriately since heat has a potential to melt it and thus making the sensors to function wrong. Altogether there are four oxygen sensors, which one is upstream from the engine and the second is downstream for each cylinder bank. Since these sensors are mounted in an exhaust manifold or pipe which shrinks when cool, they may be rather tight when the engine is cold; if one lubricates the mounting threads with an oil, it will be easier to unscrew them but one has to exercise care not to burn the fingers as the engine is running. First of all, check that the ignition key is off and securely lift the vehicle with help of jackstands. The upstream sensors are positioned on the outlet of exhaust collectours above the upstream catalysts, the left upstream sensor is situated above the left catalytic converter while the right upstream sensor is situated above the right catalytic converter. To replace an upstream sensor, find out the position of the upstream sensor, follow the lead of the electrical wire till the connector and then detach the wire, use a wrench to remove a sensor by unfastening its nuts with anti-seize compound then tighten it with the recommended torque. The process of installation is done in the opposite way as the removal one. The downstream sensors are fitted on the front exhaust pipe assembly upstream the downstream catalysts; the location of the downstream sensor is to loosen the electrical connector and to unscrew the sensor using an oxygen sensor socket or wrench, applying anti seize compound on the threads to tighten them to the specified torque On the installation, the process is reversal to the removal.