Hi all.

I just replace my front 02 sensors and the left and right were different looking when I pulled them off.

Both of the replacements looked like the left. I googled some images and it looks like the right one might have been a Bosch?

I just wanted to double check that both of the front 02 sensors should / can be the same and is part MHK100920

Thanks.



Left and right, in correct position as they were on the car.

Left (passenger side) old sensor. Both new sensors looked like this.

Right old sensor, this one looked different from both of the new sensors and the left old sensor.

 

The physical appearance of the sensor is irrelevant. Different brands are physically different.

Here, for example, is the upstream Walker O2 sensor for the DII.And here is the upstream Bosch brand sensor.Either is fine. Looks to me like your truck maybe had one Walker sensor and one Bosch sensor. Not a problem.

 

Well got the new ones on and the passenger one is smoking like crazy. Has anyone seen this before? I figured it might be some penetrating fluid or anti-sieze burning off but it is smoking for a while and doesn't seem to be stopping.

 

Yes, penetrating oil will burn off, but it will stop smoking. Just make sure it is torqued down so you don't have an exhaust leak, and all should be well in the end.

Scott

 

Thanks @skucera

It was smoking a lot so I pulled it out to see what was going on. It turns out some of the anti-size compound that they included in the box had got past the threads and on the sensor itself. I cleaned it up so there was no compound past the threads and it no longer smoked.

 

Still didn't fix the rough Idle. I am thinking it is an exhaust leak for sure now. I can hear a little bit of ticking that sounds like exhaust leak on the driver side.

 

Jason, exhaust leaks aren't usually a cause of rough idle. Have you looked for vacuum leaks, or fouled plugs, or clogged injectors yet? Given the age of our Discos, any of these are plausible.

Before I changed the head gaskets in my RRC about ten years ago, I had an uneven idle that was caused by a leak of coolant into one of the cylinders. I could tell because all but one of the spark plugs were straw colored, but one was steam cleaned and absolutely pristine looking. Also, I had a little extra white steam at the exhaust on start-up on fall mornings.

I mentioned clogged injectors because my boss had that problem with his BMW X5 4.4. He took his injectors to Oregon Fuel Injection where they tested them before cleaning them, but two were too far gone to clean, so he bought a new set of eight.

Anyway, there are lots of potential causes for a rough idle, so eliminate each in turn before spending a lot on parts that may not fix the issue.

Scott