P0136 Oxygen Sensor Bank 1 Sensor 2

[Jyosua]

My check engine light came on today, with the code in the title. I assume this points to a bad sensor.

A) Is it absolutely certain from this code that the sensor is the problem?

B) How do I replace this? I'm a mechanical newb.

Thanks!

 

[bobflood]

My check engine light came on today, with the code in the title. I assume this points to a bad sensor.

A) Is it absolutely certain from this code that the sensor is the problem?

B) How do I replace this? I'm a mechanical newb.

Thanks!

A) No, but that's the way to bet.

B) P0136 - Oxygen O2 Sensor Circuit Low Voltage (Bank1, Sensor2). Bank 1 is passenger side; Sensor 2 is in the exhaust pipe behind the catalytic converter on that side. Replacing O2 sensors is conceptually pretty simple - unplug and unscrew the old one, then plug/screw in the new one. Depending on the engine, access may be an issue, and getting the old one loose can be difficult due to rust and corrosion.

 

[Jyosua]

I've got a '97 Mountainer, 5.0L V8. I'd imagine it's pretty similar to your vehicle.

The sounds decently simple. Is there any chance you could take a picture of the location and circle it in paint or something? Sorry for the bother! Alternatively, if you know of a tutorial or something, please do let me know. I did a search on the forums, but didn't find instructions.

If you don't mind me asking, what type of access problems might I encounter, and how do I deal with them?

 

[bobflood]

I've got a '97 Mountainer, 5.0L V8. I'd imagine it's pretty similar to your vehicle.

The sounds decently simple. Is there any chance you could take a picture of the location and circle it in paint or something? Sorry for the bother! Alternatively, if you know of a tutorial or something, please do let me know. I did a search on the forums, but didn't find instructions.

If you don't mind me asking, what type of access problems might I encounter, and how do I deal with them?

Sorry, but I don't have any way to do pics; and it's been a couple of years since I did mine. By "access issues" I mean being able to get wrench or an O2 socket w breaker bar on the old sensor with enough room to turn it. I have access to a lift, which is much easier, but the job can be done with the vehicle up on ramps/jack stands.

Best advice I can give you is:
- Slide under pass side of truck just behind front tire and look for the sensor. It will be in the exhaust pipe behind the second cat but in front of the muffler.
- There will be either three or fours wires (probably four) coming out of the sensor. (IIRC, all four O2 sensors plugs are on top of the transmission, so the wires will run up on top of the transmission to a socket. But I may have my vehicles confused - I have several different ones I work on.)
- Go to one of the auto parts stores and rent/borrow an O2 sensor socket set.
- Get some PB blaster to spray on/around the socket. Hopefully, this vehicle has spent it's life in the South, so rust won't be so big an issue.
- Unplug the sensor before you unscrew it. You can cut the old wires off to get them out of the way - but then you are committed to the replacement!
- Don't buy a "generic" O2 sensor replacement. Get one with the correct wire lenght/plug already on it; worth the extra money.
- Make sure there is anti-seize on the new sensor; most come with it - if not, buy some and add it. Screw in the new one before you plug it in.

Good luck - sorry I don't have pics - maybe someone else can post some???

 

[SoNic67]

The passanger side connector is very difficult to reach from outside on a V8. It usually involves removing of the center console, front seats, carpet and under that it is an access panel.
I am looking into changing those O2 sensors myself and the picture that is here on site from a V6 doesn't match what you have on V8.
http://www.explorerforum.com/forums/showthread.php?t=73275

I did use lots of penetratig fluid and still could not budge the sensors. I will try again this week, maybe the fluid worked a little more the rust. Of course, you might be in a better shape, depending of how much salt your undercarriage saw.