Ok guys so trying to remove the post cat drivers side O2 sensor from my 97 5.4 F150. I sprayed penetrating oil on it, and used a O2 socket and it was so hard it actually spread the socket and slipped halfway so the socket was jammed hard but not on right. Got the socket off, but it obviously wasn't gonna get the job done. Tried using a box end wrench after cutting the cord off the sensor, tried fitting a pipe wrench in there but it is right above the torsion bar so it can't turn enough to get a good grip, this being an 18'' pipe wrench the smallest I have at the moment. Tried using good ole vise grips and it just seems to eat the teeth of the grips and the edges of the sensor.

I have used penetrating oil... heat... hammered at the base with a drift to hopefully loosen up rust... and still it WON'T TURN AT ALL! Any advice guys?

If I saw off the sensor and leave only the hex side I could use a die grinder to flatten the sides again and probably get a good socket on it, but would innerds fall into my pipe? Not sure how O2 sensors are built on the insides. Also thought if I cut it off I could use a bolt out tool to grip the edges and possibly turn it out.

Let me know your thoughts, ideas.

schmidty

 

You will probably need to drop the y-pipe to get better access to it.

 

Damn fools at Ford. They build such great products, but someone needs to talk to their exahust engineers and tell them what happens when you take a stainless steel O2 sensor, and you thread it into a stainless steel O2 boss, without using anti-seize.

When the stainless rubs against stainless, the ultra thin chrome layer is scraped off. When oxygen gets to the surface, the steel repairs itself. When this happens the two steels literally weld together.

What we had to do to my dad's Dakota was leave the sensor in there, put a new hole close by, and weld in a new port. The new port was ordinary cold steel. Stainless steel will not fuse to normal steel. The normal steel might rust a bit, but when you torque on it, it will still break loose.

 

Here is a O2 sensor. As you can see there is a rather solid threaded section. If the end did fall into the exhaust I don't believe that it would create much of a blockage. I 2nd the idea of removing the Y-pipe in order to access the sensor for work in this situation.

 

I ended up having to replace the Y-pipe on my 91 F250 after the O2 sensor failed.

 

Ok guys, I got it out and replaced. I ended up sawing the end off with a sawzall, then using a chisel to break up the porcelin on the inside. Once I had that worked out all I had left to work with was the 6 point threaded portion. The darn thing was chewed and stripped to beat all, but I referenced the Metric/Standard size comparison and saw that a 22mm is just under a 7/8'' so I pounded a six point 22mm on there and low and behold she broke loose and spun out with some powdered rust. The threads were still great, so I got the new one and spun it right in.

Thanks for the input guys, hopefully this helps somebody someday!

P.S. ONLY USE THE PROPER TOOL OR A SIX POINT SOCKET WHEN IN A PINCH!!! 12 points are junk for stuff like this if its really stuck.

 

AMEN! And doesn't it tick you off when someone puts a 12 pt. bolt in there just to hack you off. The tool companies and the bolt companies have a pretty good racket going.