97 Mountaineer

I have a bad O2 sensor, Bank 1 Sensor 2, malfunction. It was loose and I retightened it but code came back. I think passenger side after cat convertor. Problem is, I can't see where the connector is? I see where the wire is going but it seems like I have to get it from inside the vehicle. Anyone ever do this one? Thanks

You're correct on which sensor is Bank 1, sensor 2. What code do you have? A code that references B1S2 doesn't necessarily indicate the O2 sensor is bad.

Does your Mountaineer have the V6 or V8? I recently changed the O2 sensors on my V8 Mountaineer, it wasn't fun. To get the rear one disconnected and reconnected, I had to bear hug the transmission, reach over the top from the driver's side with my right arm, and reach over the passenger side with my left. Not the most comfortable, but it did work.

-Rod

It is a V8 5.0L. My son currently has the car. I don't remember the exact code numbers but the autoxray 6000 said malfunction.

Do you have the PC software for the Autoxray? If so, you can datalog the oxygen sensors, then download the data to your PC to see if they are functioning properly.
If you haven't connected the AutoXray to another vehicle since the Moutaineer was scanned, you should still be able to review the codes.

You can replace the sensors as part of routine maintenance, but depending on the code, it may not fix the real problem.

-Rod

Hopefully I'll get to it tomorrow and post the codes.
OK, It is a P0141.

The code P0141 indicates a short to ground, open, or short to VPWR in the HO2S heater circuit, bank 1, sensor 2.

This may or may not be a problem with the oxygen sensor. According to the factory service manual, possible causes are:
-- Shorts to B+ in harness or HO2S.
-- Water in connectors.
-- Cut or pulled wires.
-- Disconnected wiring.
-- Open VPWR circuit.
-- Open GND circuit.
-- Low battery voltage.
-- Corrosion or poor mating terminals.
-- Damaged HO2S heater.
-- Damaged PCM.

If you decide to just replace the sensor and find the Check Engine Light remains with the same code, be prepared check for any of the above conditions.

I think the datastream mode of your AutoXray EZ-Scan 6000 should allow you to monitor the individual sensor heater current draws.

-Rod

Thanks for the info but I am a novice using the scanner. Can you shed some light on the data stream thing? Basically, I'm a parts replacer guy.

I've loaned out my EZ-Scan 5000, so I can't get in to menus to walk you through it currently. My recall is you scan the car for codes first, then you press the DATA button. A menu will be displayed with various options. One option should be "Operational data." Cursor to that option and press Enter. After a couple of seconds, a list of data will show up with values to the right. Use the cursor arrows to toggle between the screens of data. Hopefully there will be four parameters for O2 heater current, probably in the form of B1S1 Htr crnt or B1S2 Htr mA.

-Rod

Turns out the manual is online. http://www.autoxray.com/publish/2006/06/13/pdf_english_94.pdf

See page 18 for monitoring real time data.

-Rod