How to remove driver side O2 sensor?

[SixFoFalcon]

At nearly 110k miles, I have a code for an upstream O2 sensor out of range. Normally I'm hesitant to swap O2 sensors before ruling everything else out, but in this case the sensors aren't too pricey and at their high mileage it's quite possible they are due for replacement, so I'd like to swap in the new sensors and see how that goes.

The passenger side was a piece of cake--the swap took all of 5 minutes using a 7/8" O2 sensor socket. The driver side is more challenging. The O2 sensor is practically resting against the engine block, which is making it impossible to slide the O2 sensor socket over it. I have to come in at an angle with the socket, and without clearance to straighten it out (it hits the engine block), I can only slide the socket down about 1/2 way toward the hex portion of the sensor. My 7/8" combination box & open-end wrench is mysteriously MIA from the tool chest, not that I'm sure I could even get that in there anyway.

Has anyone had success with an obstruction wrench or flexible/pivoting box wrench or flare nut wrench? I'm willing to buy such a specialty tool, but I don't want to spend all day running around picking up different tools on a trial and error basis.

And before anyone suggests removing the Y-pipe from the manifolds, understand that the flange bolts on the driver side are both rounded off. I'd probably have to do some surgery w/ a cutoff wheel to go that route.

 

[disciplerocks]

When I replaced mine on my Focus, I bought the regular socket and got the front then had no room to get the back one out. I had to go and buy the L shaped "crows foot" socket. Here is a pic.

 

[t0x1k]

It's a very hard and long process but a smallish breaker bar that ratchets(or you'll be flipping the wrench around a lot) and the regular oxy wrench will do the job.

 

[SixFoFalcon]

Thanks guys. I ended up going to AutoZone and the woman at the parts counter searched through the tool rental boxes until she found one of the O2 sensor tool kits that had the 7/8" crow foot socket included. I had about 15° of room to turn my socket wrench from underneath the truck. The tricky part was removing the crow foot socket every 1/6 of a turn, since the protruding portion of the socket would eventually run into the engine block (or maybe it was the trans bellhousing... either way it was an immovable object).

So all in all it took about an hour and a bit of knuckle skin to swap that driver side O2 sensor. It never did get loose enough that I could turn it by hand, so I had to re-orient the crow foot socket and wrench about a dozen times.

Upon removal, I saw that two of the sensor's wire leads were damaged. It looked like they had been smashed during some previous repair job. After installing the new sensor, I made sure to route the wires out of harm's way before reconnecting the plug to the harness.

Hooked everything back up, started the engine, did the PCM "re-learn idle" procedure, and all seems to be well now. We'll see if the MIL stays dark and the MPGs improve in the near future.

 

[disciplerocks]

Good to hear. Glad it worked for ya!

 

[Spowerback]

22mm-7/8"

not forget to put this at new part

 

[disciplerocks]

7/8"

He's got it finished. Read the thread before posting.

 

[Spowerback]

ok good

 

[t0x1k]

Did you have fun with hooking it back up to the harness? I was on the side of the road with my hand between the fire wall and engine using my middle and index finger to coax the two connectors back together.

 

[SixFoFalcon]

Considering all the crap I went through yesterday, plugging it into the harness was nothing!

In addition to the O2 sensor swap, I spent a good 3 hours with the dash apart, fixing stuff.

The horn switch contacts were dirty (had to punch the airbag whenever I wanted to honk the horn) so I pulled the airbag, cleaned the horn contacts w/ 800 grit sandpaper and protected them with dielectric lube.

Then I pulled apart the multi-function switch because I was having occasional problems with the left turn signal not flashing. Took me a good 30 minutes trying to fit that puzzle back together after I cleaned and lubed all the internals.

Finally I performed a long-overdo gauge cluster swap (I wanted to upgrade to a tachometer) which meant ticking the "new" odometer forward to match the truck's mileage. Then I had to drive around comparing the MPH on my GPS to the MPH on the new speedometer, pulling over every few minutes to reposition the speedo needle until I finally got it just right.

Also installed a new battery, changed the oil, and some other easy stuff.

So yeah, plugging into the harness wasn't so bad... from the sounds of it, the location is a little more accessible on my '99.

 

[fourwheelford]

A hydrolic wrench can sometimes come in handy in situations like your o2 sensor problem, they are at an angle that makes getting at that stuff pretty easy. That plus a three foot breaker bar and some penetrating lube takes care of stuff like that. At any rate it sounds like you had an enjoyable time taking care of all the fun stuff

 

[kevin2000]

I have the same issue but have ALL the tools necessary and previously mentioned and still CANNOT get EITHER O2 sensor to budge! It appears I am gonna have to drop the Y-pipe to get to these rusted on POS's.

Plus I have to do this outside in the Pacific NW in the rainy season!!

 

[JP02XLT]

Try breaking them loose when they are hot, That is how I had to do mine, I sprayed them with PB Blaster (penetrating oil) several times while cold & let it sink in, before trying it with it with the engine / exhaust up to temps. They came right out when hot.

JP02XLT

 

[cp2295]

At nearly 110k miles, I have a code for an upstream O2 sensor out of range. Normally I'm hesitant to swap O2 sensors before ruling everything else out, but in this case the sensors aren't too pricey and at their high mileage it's quite possible they are due for replacement, so I'd like to swap in the new sensors and see how that goes.

The passenger side was a piece of cake--the swap took all of 5 minutes using a 7/8" O2 sensor socket. The driver side is more challenging. The O2 sensor is practically resting against the engine block, which is making it impossible to slide the O2 sensor socket over it. I have to come in at an angle with the socket, and without clearance to straighten it out (it hits the engine block), I can only slide the socket down about 1/2 way toward the hex portion of the sensor. My 7/8" combination box & open-end wrench is mysteriously MIA from the tool chest, not that I'm sure I could even get that in there anyway.

Has anyone had success with an obstruction wrench or flexible/pivoting box wrench or flare nut wrench? I'm willing to buy such a specialty tool, but I don't want to spend all day running around picking up different tools on a trial and error basis.

And before anyone suggests removing the Y-pipe from the manifolds, understand that the flange bolts on the driver side are both rounded off. I'd probably have to do some surgery w/ a cutoff wheel to go that route.

I pulled my 3.0 off my 99 recently and had to remove the driver side o2 sensor because it was in the way of the flange bolts. All I can say is that you gotta find a way, I just used a box end wrench.. It was a timely process but I got it done