O2 Sensor Problems

[OMGLOLetcetc]

When I first got my 98 Explorer (EB Edition, V8, 5.0) all was well. It drove good and it seemed really reliable. Strong, solid truck.
After a few weeks, my check engine light came on. The truck was still running fine, I wasnt too worried about it. I took my truck to a Auto Shop and they hooked up the tester to it. Said it was a bad O2 sensor. They said it wasnt a big deal. Truck would still run fine. No worries.
Here lies the problem. My truck is getting close to 9-10MPG. Yeah, thats no good. I heard the o2 sensor is most likely the reason.

Anyways, my question is, how hard is it to fix the sensor? I heard my truck might have 4 of them, would the diagnostic tester tell me which one is bad?? Where are they located exactly??

I did search, but found mixed answers. Any help you could give me would be awesome.

 

[aldive]

After a few weeks, my check engine light came on. The truck was still running fine, I wasnt too worried about it. I took my truck to a Auto Shop and they hooked up the tester to it. Said it was a bad O2 sensor. .

What was the exact code?

More often than not an O2 code is not the result of a defective O2 sensor, but of something upstream of the O2 sensor.

Have you scanned the O2 sensors for function?

Here lies the problem. My truck is getting close to 9-10MPG. Yeah, thats no good. I heard the o2 sensor is most likely the reason.

That mileage is pretty bad. I would resolve the issue asap.

Good luck ....

 

[OMGLOLetcetc]

What was the exact code?

More often than not an O2 code is not the result of a defective O2 sensor, but of something upstream of the O2 sensor.

Have you scanned the O2 sensors for function?
.

Not exactly sure what the code was, they just said it was a bad O2 sensor. Im going to Aamco this week so they can scan if for free and give me all the details on the code.

 

[ThePhoenix]

just dont change out the o2 sensor yet....

 

[aleej]

get the code or codes and search them sometiems like previously stated something upstream could be causing the issue and it will look like and even soetimes give you and o2 code... but like the maf sensor may eed cleaning... w/e any way when was the last time u did plugs and wires that may help as well with the running rough.. and ya dont just go changing o2 sensors they are expensive and a pain in the arse to do....