If there are specific hazards or issues with an O2 sensor then adjust these instructions accordingly.
There are four simple steps to try initially:
1) Clean up the seized fastener... use a combination of degreasers, detergents, abrasives. DON'T use wire brushes in this instance, stick with plastic. This sets things up for the next step...
2) Search for the term "penetrating lubricant". These are specially formulated to squeeze into the small spaces in fastener threads. Use the lubricant liberally. Use plastic brushes to work it in, further cleansing the area.
3) Try to rock the fastener in both directions... particularly effective if it starts to come undone then jams. Add more lube as you go... it should rock a little further each time until it frees up. if not...
4) If seized absolutely solid try a freeze and release spray... very effective and much safer than heat around delicate electrics. Check the product to ensure it is safe around electrics as this is a special situation.
Remove the vacuum hose from the O2 sensor. Remove the wiring harness. Remove the O2 sensor retaining screws. Reverse the process to install the new O2 sensor.
To change an O2 sensor you need to disconnect the wiring harness from the sensor. Use an O2 sensor socket and ratchet set to remove the old sensor and replace with the new one.
If you buy a o2 sensor socket at a parts store, and you have a propane hand torch, and wd40,your halfway done. Stubborn rusted may need heat to remove. disconnect harness on 02 sensor, slide on your socket and break it loose
You can't.
unscrew it
the o2 sensor is located in the exhaust manifold. As you pop the hood and look at the engine, you should see a silver colored heat shield. Unplug the old O2 sensor. Then remove the heat shield. Its easier this way (10 MM bolts). Get a O2 sensor socket and remove the sensor and replace. The rear sensor is located in 1 0f 3 places. Either before in or after the catalytic converter. For this one you just get the O2 sensor socket and remove. (When the engine is cold) Madd Dogg 40/40
Remove the vacuum hose from the sensor. Remove the sensor retaining screws. The sensor will come off. Reverse the process to install the new sensor.
It has a conector, just un plug it. Then remove the 02 sensor from the exhaust.
The O2 sensor on a 2000 Hyundai Elantra is removed by disconnecting the wiring harness and unscrewing the sensor from its housing. It can then be removed from the vehicle, inspected, and replaced if needed.
To remove the sensor, turn it counter clockwise. Be sure to coat the threads with anti-seize compound when replacing.
The first O2 sensor is tough to get to, you need to remove the heat shield off the exhaust manifold, then you'll see it on the left side. If you have large hands like I do, you'll need to loosen the radiator. The second O2 sensor can be accessed from underneath the car, or if you remove the starter, you'll see it below.
Installing an o2 is very easy. Remove the neg. battery cable. Then disconnect the o2 power connector. Feed the wire through the box end of wrench. Finally, unscrew the o2 sensor.