O2 sensor question

[White Lincoln]

As you may have read several months ago, I had codes 137 / 173 which basically where saying the O2's are out of range and running too rich for the PCM to compensate. Last week I replaced my O2's with a pair I bought last year. I ran diags today and the 137 error is gone, but the right bank o2 is still showing 173 "running rich". Since I have my car running pretty well now, the O2 may be the issue since the left back error went away with an O2 swap. My thought might be that after the last several years of running my engine with my timing off may have damaged the O2's.

I read an article on "cleaning" the O2 using a propane torch. Anyone done this before and the cleaning showed enough positive change to not buy a new set?

The O2's I had in before last week were BOSCH 15716.
The O2's I replaced the one's above with are Bosch 15717.

The diff from what I read is the length of the connector cable. 15716 has short connectors and 15717 has long connectors. Otherwise, they both are rated for my 94 3.8l.

Amazon has the Bosch -16 O2 for $19 and says it is a downstream (which does not matter on my car) and an exact fit.
The - 17 O2 is $29 and just says "Compatible with Select 1989-16 Ford, Jaguar, Lincoln, Mazda, Mercury"

RockAuto has the MOTORCRAFT DY1401 for $45. I'd buy that if I knew I was not wasting money and the Bosch for $19 would probably do.

Thoughts? Comments?

 

[White Lincoln]

I just noticed something.

The 94-95 Mustang 3.8l uses 4 sensors, two upstream and 2 downstream.

The upstream is a BOSCH 15719 and the downstream is the BOSCH 15716, the one recommended for the 94 3.8l Cougar.
*Ignore this... the 15719 is for upstream for a V8, not a V6. Geez... these parts sights can really mislead you.

Should I be using an upstream sensor instead of a downstream (since we technically do not use a downstream O2)?

NAPA says do not clean, replace. But there are tone of articles on cleaning an oxygen sensor. I also found a lot of ways to test an oxygen sensor.

I think I will be testing the O2's to verify they are working or damaged. Seems an easy way is to (as mentioned) heat the sensor to see if it produces low voltage, set voltage no matter the heat, or nothing at all. 2nd two indicate it is bad.

Thanks for reading!

 

[1997ThunderbirdLXV6]

If you have a fault code pending or confirmed on one bank only, your first step in my opinion should be to swap the sensors between banks and see if the fault code swaps sides, too. If yes, blame the sensor.

I posted about an O2 code a while back, though that was a downstream code. My car is a 97; not sure what year the downstream sensors were added.

My car had three NTK (or whatever that brand was) and one Bosch sensor, the latter being the problem. When monitoring the sensor readings real-time via my OBD2 app, the Bosch sensor always read odd. I'd recommend against the Bosch.

Here is my old thread. Not directly related to your code, but still good reading about O2s including plenty of advice from expert members:

P0156 is back

Ugh. Alright, some of you may remember that I had this code last spring. Bank 2, sensor 2, oxygen sensor rear/left. Back then, all I did was reposition the connector which kept hitting the underbody. The code never came back (till now), and I eliminated an annoying rattle in the process...

forum.birdcats.com

 

[White Lincoln]

Thank you 97. I heard the same about Bosch and these are not old enough to go bad like that. I bought a couple off brand and we'll see later this week if the code goes away when I replace the current o2s. If the new ones go bad, I am going motorctsft.

 

[Grog6]

NTK makes them for ford.

 

[KevinVarnes]

I've heard of cleaning with a propane torch, but I've never bothered trying. I usually just monitor O2 sensor voltage via a scanner and replace them it it is not reacting, but I don't think you have that ability with the OBD-I on your car. Given that, 1997ThunderbirdLXV6's advice of swapping them side to side and seeing if the code follows the O2 sensor isn't a bad idea. I've used Borscht sensors on these cars before without any issue. They also make really good dishwashers.

 

[White Lincoln]

I've heard of cleaning with a propane torch, but I've never bothered trying. I usually just monitor O2 sensor voltage via a scanner and replace them it it is not reacting, but I don't think you have that ability with the OBD-I on your car. Given that, 1997ThunderbirdLXV6's advice of swapping them side to side and seeing if the code follows the O2 sensor isn't a bad idea. I've used Borscht sensors on these cars before without any issue. They also make really good dishwashers.

Did you mis-spell the word Borscht? Cause I think your missing an i....

I soaked them in gasoline overnight. What the heck, I can't dance so this was the next best thing.

 

[White Lincoln]

FYI: I ran the voltage tests on the Borscht O2's and they did what they are supposed to. Hook up the grey and black wired posts (I think grey is +) to a VM Meter, turn it to millivolts (200 at first then as the voltage output increases, change to 2000) and heat the sensor with a propane torch. If the O2 is bad, it will have a constant voltage or no voltage, if it's good, it will climb up to around 800mv and stay there until heat is removed. You will notice, when the sensor is at 800mv, it is red hot.

Hope this helps someone else down the road.