Oxygen Sensor Replacement $$

[danwho]

Don't use a crescent - you can round the thing off.

You should be able to get a 7/8" end wrench in there, or you can get an "Oxygen Sensor Socket" - it's an "extra-deep" 7/8" socket with a groove milled down one side to clear the wiring.

Take about 5-10 minutes, as said. It's easier to change when it's a little warm, and the new sensor should have never-seez on the threads already - apply if not. The new sensor gets torqued to ~20 pound-feet (do not overtighten, or you'll end up paying someone to change it next time...)

5-90

From the 1st page

 

[UNCC_99XJ]

If you don't have the correct wrench, go to Advance (or maybe even Autozone) and rent it. The tool kits will come with about 2-3 different sizes...just put the one that fits on a ratchet and have at it.

Heck at Advance, if the customer wants to change the sensor out in the parking lot, we won't even bother charging them to rent the tool and return it 5 minutes later...too much paper work.

 

[mfascuba]

BTW, don't waste your time or money with the crown O2 sensors from quadratec - I bought two of them and still got check engine lights, replaced with Bosch and the CEL went out and the mileage went up a couple mpg. mine's a 97 4.0 sport NP242 AW4 auto W/ stock gears and 31's.

Mark

 

[LazersGoPEWPEW]

I'm going to get the bosch ones from Advance. Just looked how easy it looks. Looks pretty simple. Hopefully my mileage will go up. I don't have any CEL yet but my MPG blows.

 

[UNCC_99XJ]

Bosch direct fit and you can't go wrong. Stay away from the Universals.

 

[kastein]

listen to the guy who said 20ftlbs max... I twisted the bung out of the side of the pipe on my friend's 98 Dodge Ram because the idiot who put the last sensor in cranked it down really tight and used no antiseize. We ended up just welding a new bung into the hole and putting the sensor in that way. Also, careful about soldering the connector on if you go that route, some sensors require a "reference" atmosphere from the trace leakage of air down the insulation of one of the leads (from what people here have told me) and therefore will not operate properly if you solder that lead because the flux will wick into the space between the insulation and the wire strands and plug it.

 

[winkosmosis]

The old sensor will probably be stuck. I'd think you should PB Blast repeatedly for a few days at least

 

[LazersGoPEWPEW]

So I went at them today. Made a retard mistake and pulled out the downstream ones instead of the upstream ones. Figured it out when the connectors didn't match right. Went and bought 2 downstream sensors since I had them out. Expensive but I won't be doing that for a LONG time again. Anyways it was pretty simple. Let the XJ warm up after spraying a bit of PB, use some man strength and unscrew. I highly suggest wearing gloves while doing this and removing the airbox for the top 2 sensors.

I had 2 bolts break off in the airbox when I pulled it out. The FSM indicated 22 ft lbs of torque for the O2 sensors so I went with that.

If I hadn't made the mistake of pulling out the wrong sensors initially it would have taken a lot less time. Overall it was a pretty easy deal. Getting them out is the hardest part. Also get the compact o2 sensor tool if you do it. It works way better than the full socket type.

Mine was an 01 California Equipped XJ.