I have a 1997 F150, 5.4L motor, 115k miles. It is currently throwing code P0131. Many have said that this code will be the O2 sensor, rather than the vacuum leak problem others have experienced. What I wanted to do was to swap the front two O2 sensors and see if the code jumps to the other side. I figured that would narrow down.

So trying to get to the passenger side O2 sucks. I already pulled out the fender liner. I also pulled the tranny dipstick tube to access it. Can't really imagine getting an Oxygen sensor socket in there - no room for a ratchet. Just curious what others have done. The passenger side looks like it could be done with an oxygen sensor socket, but we'll see.

I was actually thinking of unbolting the exhaust pipe right in front of the cats, from the exhaust manifold. Anything I should be careful about there? Would this make it easier? Is it easier to get the O2 sensors out when it is hot? Or cold? Any help here would be greatly appreciated.

 

Use a good penetrating fluid [Seafoam brand Deep Creep] and a 22mm wrench should do the trick. You've got the inner fender out of the way so you shouldn't have any other problems. I really wouldn't take the exhaust off, rusted exhaust bolts can become a pita.

 

I sort of figured the exhaust bolts could become difficult and possibly break. Don't really want to go that route. But it doesn't exactly seem possible to get a 22 wrench in there either. At least not in such a way that I could actually get any leverage to loosen up the sensor.

Has anyone here actually used one of those oxygen sensor sockets on the passenger side sensor? If so, what was your ratchet/extension (if any) setup? I know people here have done this task because there are lots of posts of "had a code, changed o2 sensor, didn't remove code."

 

Front O2 sensors on my 98 5.4 were a pita especially the P/S. I went through 4-5 O2 sockets (I even modifed ones). I used Qxy/Act torch to heat O2 bung up and when bung is cooling down sprayed with PB Blaster. I then used a VW O2 sensor tool (shallow socket w/ opening). I even had to grind it a little to make it work. The Ford factory style O2 sensor socket didn't work even with heavy grinding. Couldn't get it on the sensor. The rear O2s I used a Lisle O2 socket with a clamp around bottom and the heat treaqtment cooling with PB Blaster. Hope this helps.

 

So if I am going to go through several O2 sensor sockets, wouldn't it just be easier to heat up the bolts at the flange where the pipes meet the exhaust manifold and drop that instead? Surely there is an easier way to do this project?

 

If you find an easer way please share as I was speaking from experience.

 

You break those flang studs you will have a big problem.I would first take it to a shop and have them read the code and tell you what bank the bad o2 sensor is.When I had a bad o2 sensor took to my buddy and hooked it up and is sat bank 1 then front sensor or something like that.

 

Those flange studs always break. Then it's a PITA. I went through that.

However replacing the O2's went well with my 98 when I did them . I used a 7/8 wrench to get them loose right after shutting the motor off..

 

With as it is to get them off there is no way I would do that. Just replace them. $100 be done with it. I got at mine through the wheel well..

 

If you are going to go through the hassle of pulling them, replace them, don't mess around with swapping them. With 115k, new ones will likely improve mileage and the way it runs anyway. Don't bother with the rear sensors, just replace the fronts. Bosch sensors from the parts store are fine, there is no advantage to OEM because Ford uses Bosch sensors anyway.

 

x2 on all of that...

I replaced an o2 sensor on my Dakota... even though it wasn't that hard to get out... it was just easy enough to get a new sensor rather than fooling around with swapping them around and playing a very large guessing game.

Also, as a recommendation... even though the Bosch o2 sensors come with anti-seize on them... add a little more. I know my local auto parts stores have little pouches for $.25 by the checkout counter. It will make it less of a hassle next time.

 

Thanks for the advice everyone. I really appreciate it.

jbrew - your idea is kind of what I was thinking, run it for awhile so it gets nice and hot. Things usually come out much easier when smokin' hot. I used to auto body work for a living and whenever I came across a super rusty bolt that completely stalled my impact gun, I'd pull out the torch and heat the bolt/nut till it glowed red. Let it sit for 5-10 seconds to regain its normal color, and it would then come off with a hand ratchet every time.

I think I might try to run over to Sears and get a short 7/8 wrench to get into the wheel well better on that passenger side. The driver's side looks doable. It just wasn't throwing the code, but I might as well replace them while I'm in there.

 

Sounds Good! But, If your going to go to Sears , you might as well buy the right socket for these O2 sensors. It's a 22mm (Same as 7/8) - Sears should have them and there probably cheaper than a 7/8 Craftsman's wrench..

Heres a pic of it -

 

Thanks jbrew. I hadn't even thought of using a crow's foot type device. That might work pretty darn good. I picked up a "shorty" 7/8" wrench at lunch. Sears is on my way home, I'll run by and see if I can get this other type. I wasn't really sure what kind of leverage I would be able to get with the wrench, but this thing looks like you could run a nice long extension back out the wheel-well and get some serious leverage. That will be great.

 

Yea , that's the 02 sensor socket they list and show a pic of in the Service Manual..

The other "Deepwell" type will damage the wires if your not carefull and you can't get the leverage like the correct one provides..