O2 Sensor Problem I Think

[emmittobie]

Hello there. Great forum. I tried doing a search but couldn't really come up with the exact information I am looking for. While driving my 2001 Ford Explorer Sport 4WD this morning, the CEL came on. I took the car to Autozone and the OBD code scanned a P0136 code. I guess it's the bank 1 sensor 2 which seems to be the passenger side after the catalytic converter. My question is how difficult is it to change this O2 sensor? I am not sure where it is located and this would be my first time changing this sensor. Am I better off just sending it to the dealer? If so, what would be an approximate amount for the part and labor? I know that the code isn't 100% telling of the problem and that it could possibly be another problem. The car seems to be driving fine. Should I reset the code and wait to see if the light appears again? The reason I ask is because one mechanic told me that he has people come in with the same problem and there are many occasions where the other sensors malfunction right after the first one is replaced. Not sure how to proceed. Sorry for all the questions and thanks in advance.

 

[Turdle]

You can do it yourself, and feel quite accoplished when it is all done

The best method, is to remove the center console--( it's only 5 bolts,unplug a connector, whack and out)

roll the carpet back, and you'll find an access panel. remove it, the o2 sensor plugs are right there!!

edit--
if you have real long and slender arms, you might be able to hug the tramsnission and get them disconnected and connected without removing the console. I don't bother--the console is so easy to get out!

 

[emmittobie]

You can do it yourself, and feel quite accoplished when it is all done

The best method, is to remove the center console--( it's only 5 bolts,unplug a connector, whack and out)

roll the carpet back, and you'll find an access panel. remove it, the o2 sensor plugs are right there!!

edit--
if you have real long and slender arms, you might be able to hug the tramsnission and get them disconnected and connected without removing the console. I don't bother--the console is so easy to get out!

That sounds good and I really do want to give it a try. Is there a diagram or a photo of these O2 sensors and how do I know which one is the one I have to replace? The last thing I want is to open up the console and then be stuck with no idea where to proceed. Thanks for the quick reply.

 

[Turdle]

There are 2 02 sensors on each tailpipe--one before the cats, one after.

You are looking for (according to info given) the rear, downstream, post cat, sensor on the passenger side. You should be able to follow the wiring easily--

BTW--it seems to me ( my memory??) the "short wire" ones are actually more money--if so, you can use the long wired version, and zip tie the excess up and out of the way to save a few $$$

 

[emmittobie]

May I ask one more question? Will the sensor reset the CEL back to normal or will it have to be reset with the OBD code machine? Thanks.

 

[Turdle]

It "should" be reset by a scanner, , however, you will, of course, disconnect the battery before performing any work?

This will reset the PCM. The only drawback to this, is the truck has to "re learn" for a bit.

 

[techieman33]

The short sensor is cheaper, I was just at oreilly's today, and the front sensors are $62 each, and the rears $42 for the short and $50 for the long ones.

 

[410Fortune]

You can also just pull the PCM/ EEC fuse from your fuse box, this will remove power from the computer and re-set it same as disconnecting the battery.

before you go buying a new 02 sensor you might want to check out the wiring leading to it, many times it can get melted or loose and cause a 02 sensor malfunction code (Although if the wiring does check out the malf code does point to a faulty sensor especially when it is a downstream/ catalyst monitor 02 sensor, not used for actually adjusting air/fuel trims)

I found one of the 3 wiring pins inside the connector on mine had been pushed into the plastic housing. I pulled it back out and the code dissapeared without buying a new sensor.

 

[Turdle]

Before replacing anything-
I looked in the chilton's manual--
PO136 is a HO2S fault, yes, but it would seem to point at the circuit, rather than an individual sensor. --hmmm, better wait for some opinions here-

edit--<<<<<<<<refresh before posting dummy

 

[aldive]

Hook up an OBD II scanner to your truck and scan the O2 sensors for function.

Many times the problem is not the sensor(s).

Good luck ....

 

[emmittobie]

Before replacing anything-
I looked in the chilton's manual--
PO136 is a HO2S fault, yes, but it would seem to point at the circuit, rather than an individual sensor. --hmmm, better wait for some opinions here-

edit--<<<<<<<<refresh before posting dummy

I'm guessing that there might be more trouble. Wouldn't changing the sensor in this particular bank fix the circuit? Would be nice to hear some more opinions on this from others who might have experienced the same problem. Thanks guys.

 

[Turdle]

This is the best, least expensive unit-if you have a laptop computer.

www.scantool.net

With it you can watch the actual sensor voltage switching--

I have 410Fortune's--lol and play with it often--

 

[emmittobie]

Thanks for all the suggestions. The funny thing is that the CEL light went out that evening and has stayed off so far. Not sure if it was just a weird isolated event or if further issues lie ahead. Will have to see.