The Mitsubishi Mirage has a single oxygen sensor located just behind the catalytic converter. Its job is to tell the car's computer what the contents of the exhaust gases are so that the computer can make the necessary adjustments to ensure the vehicle runs properly. When the car starts to idle rough, it may be time to replace the sensor. In this case, the project vehicle is a 2002 Mitsubishi Mirage, but the process is similar for other vehicles as well.
Raise up the front of the vehicle using the jack and set it on the jack stands. Make sure that the vehicle is solidly on the stands before crawling underneath it.
Locate the oxygen sensor on the exhaust, which is just behind the catalytic converter, underneath the front seats. This will stick out perpendicularly from the tubing and have a wiring harness pigtail coming out of the end. Unplug the wiring harness from the oxygen sensor using by hand.
Place the oxygen sensor socket onto the ratchet then put the socket onto the oxygen sensor so that the wiring from the sensor leads out of the hole in the side of the socket. Then loosen the oxygen sensor from the exhaust and discard it.
Open up the container of anti-seize and use the provided applicator to apply the fluid onto the threaded area of the replacement sensor. Make sure you don't touch the end of the sensor with the fluid; otherwise, you risk fouling the sensor.
Thread the replacement sensor into the threaded bung on the exhaust with manually to start, then tighten it in place using the 3/8-inch ratchet and the oxygen sensor socket. Plug the harnesses back together by hand.
Raise the vehicle off of the jack stands and place it back on the ground using the jack.
