Replacing o2 sensor on a 1998 Explorer

[Zom]

Is it difficult? Any suggestions to make this go smoothly would be greatly appreciated.

[khadma]

Use Bosch or OEM parts - I am sure that Ford uses Bosch O2 sensors.

There are O2 sensor sockets available, but I just use a proper sized open end wrench.

Disconnect the battery - doing this will shut down the computer and will reset it for the new sensor.

I put a very little spray of penetrating oil at the joint of the sensor and exhaust pipe. Let it sit for about a half and hour, then go about removing sensor.

MAKE SURE THE NEW SENSOR STAYS CLEAN AND OIL FREE!
Especially the electrical connector end - dirty connectors can throw a code.

After all this, reconnect the battery and take the truck for a drive to reset the computer. Make sure you can drive in different speed conditions so the computer can relearn it's parameters.

[shorod]

Which engine does your Explorer have? You will have either 3 or 4 oxygen sensors, which one or ones are you planning to replace?

-Rod

[Zom]

Thanks for the replys.

I bought it at Auto Zone. It is a Bosch brand. The guy said that it is on the drivers side of the engine on the exaust. I confirmed this by checking the Auto Zone website.

I only bought one because the guy that did my "Check engine light" test showed me on the tester what was needed.

On a side note. I took it out of the box today. The damn thing looks like it has already been used. The end that screws into the manifold is "blued" and the wiring looked kinda dirty. I'm going to stop by there Monday and show it to them. At the chance of looking like a Moron.

[shorod]

The bluing of the sensor end is normal. Does the antiseize on the threads look disturbed?

It would be interesting to know what code your Explorer came up with. This is the problem with having codes read for free by sales people. The code may have been a "Lean condition on bank 2" so the sales guy thought, "Hmm, the lean condition is reported by the O2 sensor and there's one of them on bank 2, the O2 sensor must be the problem" so he sells you an Bank 2, Sensor 1 oxygen sensor. When in reality, the O2 sensor is working perfectly and indicating a vacuum leak or fuel injector problem with bank 2.

-Rod

[Zom]

Originally Posted by shorod

The bluing of the sensor end is normal. Does the antiseize on the threads look disturbed?

It would be interesting to know what code your Explorer came up with. This is the problem with having codes read for free by sales people. The code may have been a "Lean condition on bank 2" so the sales guy thought, "Hmm, the lean condition is reported by the O2 sensor and there's one of them on bank 2, the O2 sensor must be the problem" so he sells you an Bank 2, Sensor 1 oxygen sensor. When in reality, the O2 sensor is working perfectly and indicating a vacuum leak or fuel injector problem with bank 2.

-Rod

Is the antiseize that grey stuff?


He showed me the read out on the tester. I honestly can't remember what it said. But being a reputable place that it is I would hope that Auto Zone would train there guys to know what they are doing. I guess I'll find out once it is installed.

So is this easier to get to from the top or underneath the auto?

Thanks

[shorod]

Then anti-seize is the gray stuff on the threads that looks a bit greasy.

I'm not sure which engine your Explorer has, or which of the 3 or 4 sensors you're trying to replace, but generally they are easier to replace from underneath. Again, depending on the engine and which sensor, you may be able to get to them from the front wheel well with the wheel removed.

You'll want to make sure that you can find the connector for the sensor(s) and you can disconnect it. You'll need it disconnected when you remove the sensor. I would also recommend borrowing the sensor socket set from AutoZone. They probably have the standard sensor socket, but there is another 3-piece set that is also used for removing sending units that will offer you a bit of variety. I needed the offset socket to replace a couple of the O2 sensors on my V-8 Mountaineer.

If your O2 sensors are not seized in the exhaust pipes, you may be able to get away with using an open end wrench, but I wouldn't recommend it. If you get a bit crooked and spin the wrench, you can round off the sensor and then be in a real predicament.

Have I asked which engine your Explorer has and which sensor you are planning to replace?

-Rod

[Zom]

shorod, The guy at autozone, if I am not mistaken said that I would find the sensor on #1 cylinder. The thing is the check engine light went out. I've been real busy with work but I am on vacation this week. I will post what engine I have tomorrow. Thanks.

[shorod]

I suspect he said #1 bank (rather than cylinder). If he said "cylinder" then either he doesn't know what he was talking about or he was having a bad day. Either way though there could be two O2 sensors on bank #1. If you'd let us know which engine your Explorer has, we could help you understand where the sensor is a bit better. I won't ask for the engine information a 4th time (see posts #3 and #7)....

-Rod

[Zom]

Originally Posted by shorod

I suspect he said #1 bank (rather than cylinder). If he said "cylinder" then either he doesn't know what he was talking about or he was having a bad day. Either way though there could be two O2 sensors on bank #1. If you'd let us know which engine your Explorer has, we could help you understand where the sensor is a bit better. I won't ask for the engine information a 4th time (see posts #3 and #7)....

-Rod

Rod. It has a 4.0 S.O.C.

Thanks for you patience.