Oxygen Sensors

[lrwjr1964]

I looked all over for this and maybe i just missed it but I have an 02 XLT with a 4.0 engine. I see 2 of the oxygen sensors, one on the intake and one on the exhaust manifolds. My question is the dealer said i might have 3 or 4. How can i have 4 if i only have one cat? I can see if i have a V8 with a cat on each side which would give me 4. Am I missing something here? Well I want to replace them at the same time since one is reading bad when i had it scanned at Advanced auto. Can somene let me know how many I should have? Thanks.

 

[mattadams]

If you have one cat, should have two o2's, one before the cat, one after. At least thats what every vehicle I've seen in recent years has had, I dont have anything as new as your explorer to look at .

 

[lrwjr1964]

On the passgnger side of an 02 explorer I see one on the intake manifold, on the drivers side there is one i can see on the exhaust manifold and the cat is also on the drivers side so i know there is one more after the cat. Well from what i learned in elementary school 1 +2 =3. So why when i told the parts guy that at the Ford dealer, he said i might have 3 or 4. 4?

 

[aldive]

You should have 4 O2 sensors.

 

[mab668]

i have been to Advanced auto a few times for a code scan and every time they told me i had a bad o2 sensor. it never was an o2 sensor

 

[aldive]

i have been to Advanced auto a few times for a code scan and every time they told me i had a bad o2 sensor. it never was an o2 sensor

A O2 sensor code is rarely due to a bad O2 sensor; the sensor is reporting trouble upstream.

 

[lrwjr1964]

About 3 weeks ago the SES light came on but went out and then on and off for about a week. I got it checked at advanced auto and it said the O2 sensor was bad. The light went out a few days later and has not come back on since. In the meantime I cleaned everything meaning the MAF and IAC. You can still feel the lag, the tranny feels like it is lagging and when i corner hard and hit the gas you can feel lag like she is going to shut off but then the tranny kicks in. I can feel the car is acting up. My gas mileage has shot way down. There is also a slight roughness to the idle. I did notice something though. When I was cleaning the MAF and IAC, I disconnected my battery and noticed that the green eye was not a solid green color like it was 7 minths ago. I can actually see the little green ball down through the eye like there is no liquid in the battery. Could this be the cause of my problems? Oh yeah, the battery gauge is in the middle or a slight tick more. And ideas?