Firewall side O2 sensor removal (03 STS)

[DaleJrLasVegas]

Has anyone else experienced the firewall side O2 sensor seizing making it impossible to remove with Impact wrench, Socket wrench, 1/2" breaker bar and penetrating solution? I spent a couple hours trying to remove the sensor. Any suggestions would be appreciated.

[OldFart]

The breaker bar is the best solution. How long is the bar? Have you tried slipping a pipe over the bar to give you more leverage? Also, have you tried to tighten it as well, sometimes turning it clockwise to tighten is enough to break it free and then you can turn it counter clockwise to loosen. Also, the FSM suggests running the engine for a few minutes to warm it up to help facilitate removal. Good luck.

[Ranger]

Have you tried running the engine to heat the exhaust manifold first?

[rockfangd]

that trick burns but works like nothing else. I have excellent luck. I just run it for about 5 minutes and voila it comes out

[BodybyFisher]

You say you used a 'socket wrench', do you mean that you are using a socket designed for O2 sensors with the cut in it for the wire? If not find the proper socket designed for O2 sensors

As noted warm up the engine to about 120 degrees NOT HOT.

Get on it with the proper socket and an 18 inch breaker bar and it will come right off. If you want soak it with a good penetrating oil first, but I don't find that necessary.

[DaleJrLasVegas]

Thanks for the suggestions gentleman. The car is now in the shop with the O2 sensor seized. They can't remove it. Now I'm waiting for a new exhaust manifold to arrive.