In the process of oxygen sensor servicing, the pigtail and electrical connector that are permanently attached to it must be handled cautiously so as not to spoil them. Do not allow oil, dirt or any other foreign matter to touch the electrical connector or sensor; avoid using cleaning solvents. Do not drop or handle rough the sensor. The negative terminal cable should be disconnected, and the vehicle jacked up securely on jack stands in order to replace the sensor. In non-turbocharged models, behind flange between exhaust manifolds and front end of catalytic converter is where upstream oxygen sensor is located. This connector will usually be found at back of engine compartment traced along its harness by electrically wiring up with a sensor inside it that needs disconnection while removing unscrewing & taking out a connector.Similarly, remove this clip before unplugging it from whatever you are indicating and take away these clips from there.Do ensure that no anti-seize compound is applied on threads if installing old one.In turbocharged models however, the upstream oxygen sensor can be seen on the right exhaust manifold itself. Separate an electrical connector and detach clips holding-sensor harnesses. As for a right-front wheel, remove it together with service hole cover in wheel housing splash shield.The oxygen sensor screws out and comes off from right exhaust manifold.For location of downstream catalytic converter you'll find downstream oxygen sensors.The respective harnessed for such sensors are traceable through their connectors which may also require removing and turning out among others.Finally undo this screw then take out any left over fragment involving catalytic converter after having unscrewed it earlier.Hence no antiseptic lubricant is necessary for application into these.