97 Explorer V8 AWD - O2 Sensor Question

[fastcougar]

My 97 Ex V8 AWD is throwing P0141 DTC's left and right (Bank 1 Sensor 2 Circuit Malfunction).

It's snowing out right now and I can't get under the vehicle to check, so a few answers would be greatly appreciated!

1) How many O2 sensors are on the 97 V8's?
2) Kinda related to #1: Are there "pre-cats" with 1 sensor upstream and 1 downstream of the cat?
3) Which side is "bank 1" ... driver's side or passenger's side of the engine???

 

[97BlackX5.0]

welcome to oxygen sensor hell.... our trucks have four oxygen sensors and 4 cats. i believe that bank 1 is the bank with cylinder 1 on it... havnt done it in a while and cant remember. bank 1 sensor 2 means its on bank one and the downstream sensor. the first two sensors are the most important ones.... you can drive around with the rear ones out and your truck will still run right but the emissions outputs may be a little off. the truck goes to a preprogrammed set of instructions when the sensor is out of range. may not be the most optimum setting but it works..... i have to change that exact sensor tomorrow... mine is out too but i have mine thawing in a garage for now. good luck ... the sensor wires are a pain in the behind to unplug... so plan on getting underneath it for awhile anyways...

 

[section525]

Don't forget you can access the o2 sensors from inside the truck under the carpet (where a floor shifter would come through). There's an access panel under there and it'll make the jobs a lot easier.

 

[V8BoatBuilder]

What these guys all said is right on the money.

- Bank 1 is the passenger side, covering cylinders 1-4.
- Bank 2 is the driver's side, covering cylinders 5-6.
- The 1st O2 sensors in each pipe actually controll and monitor the A/F ratio. They are important.
- The O2s in between the cats monitor the first set of cats. You can remove these O2s and get "simulators" with no effect on performance. The second set of cats is not monitored.
- To change the O2s, you NEED to access the wiring harnesses through the floor, unless you have thin bionic arms. Removing the center console is simple, and then either lift the carpet or cut a small hole under the console (that's what I did) to access the panel. Post back if you want more info, a lot of us have removed the console for O2 sensor access.

 

[zmanwth]

97 Mountaineer, 5.0L. I need to replace bank 1 sensor 1. I cussed when I found it. I could barely touch the connector with the longest screwdriver I have. Do you have any tips on removing the center console and exactly where to make the cut in the carpet. Any help would be appreciated.

 

[97BlackX5.0]

i think those are farther forward and wouldnt be accessable by taking out the console.... i have unplugged and removed all mine without taking the console out.... (was a pain in the a@S) but i did it.... sure you have the first sensor...