Frozen O2Sensor hard to remove on exhaust manifold side/ top front of engine? I got a Snap-On O2 Sensor deep Socket 22mm and i tried to remove it with my 1/2" drive. I used a breakerbar and the socket seems to slip the O2 Sensor. The sensor is somewhat rounded and i am scared to round it more?

Also, Frozen can't remove; I drove my car and it got really hot, put WD40 and still can't come off? It seems rounded what is a good way to remove it?

Will a impact gun work? What tool I need advice? Tec Tips need help pls

 

You need to heat the area where the o2 screws in.

 

throw that wd40 in the trash can. Get some PB Blaster from the parts store. Its in a white can with comic looking writing on it and a Yellow cap.
WD40 is just lubricant, PB is penetrating oil, its gets down in threads and breaks up rust

spray on, let sit for a minute, then use the open end of a wrench to go on the least rounded edges of the sensor, lightly tap the wrench with a hammer if needed

 

Thanks-

 

dont use a impact gun you will break the crap off.
do what boostnbe said use a wrench and if it feels like it might round off more, stop.

 

pb is your friend, but you may have rounded it out to much for a wrench or socket. Grab some big vicegrips if you did and put them on in a way you could use a bar as leverage. Put anti-seize on the new o2 sensors threads, just make sure you dont get any in the sensor.

 

Use brake fluid. It displaces moisture/rust. If its rounded, you could cut the wires off of it and hammer a socket onto it, then turn it nice and slow back and forth, work it out.