Question: How do i remove a seized oxygen sensor on a toyota highlander v-6?

(Posted by: Jim on 2010-07-29 09:44:51)

The Manifold (rear, nearest the firewall) O2 sensor id seized in the exhaust manifold. What is the best way to remove it?

Posted by: gimpalomg on 2010-07-29, 10:03:29

The first thing you need is proper tools. An 02 sensor socket is one of the better ways to go. Personally I prefer a quality box end wrench if there is room to use it. If you use a socket I would suggest a breaker bar in lieu of a ratchet. If you have one and there is room to use it, an impact wrench is a very powerful tool. I would try a real penetrant, WD-40 will be tempting but I would get a single purpose penetrating fluid. Apply it when cold, let set for a few hours and give it a try. If you can break the seizure don't force it out. Apply more penetrant and begin working the sensor in and out; hopefully gaining a bit with each cycle. If you can't break the torque apply more penetrant and repeat the process. If a second try fails to break the torque then start the engine and when the manifold reaches full temperature try it again. If and when you finally succeed be sure to use an anti-seize compound on the new sensor; and don't be stingy. Also you should check the threads in the manifold. Frequently there will be a transfer of metal from the sensor to the manifold. If you find any be sure to remove if prior to the new installation. Good luck, those things can be a real problem. GIMP

Posted by: Kenny on 2010-07-29, 09:59:30

Buy a can of PB Blaster or Liquid Wrench, soak it for 15 minutes or whatever time you want, insert the O2 removal tool, put a long pipe on the ratchet for more leverage and hope for the best.