[1997ThunderbirdLXV6]

I guess it had to happen at some point...ugh.

Next steps? There are no drivability issues at this time.

 

[1997ThunderbirdLXV6]

It shows 1 of 2 stored, is there another code?

The guy told me there was one code
I don't have a reader myself.

I disconnected the battery for a few minutes, then drove for a few minutes, and the light did not come back. Maybe I fixed it? Lol...

 

[1997ThunderbirdLXV6]

You can clear codes by pulling fuse 15 under the hood, and

I actually just disconnected the battery for a few minutes. The light did not return on the next drive.

I'm thinking that if there actually is an issue, the light will come back pretty soon. If it doesn't come back, then maybe it was some sort of false alarm (?).

 

[1997ThunderbirdLXV6]

With your reader

That was the guy from Advanced Auto's reader. I don't have one. I know, crazy: Martin, identifies as car enthusiast, yet does not have a code reader. What's wrong with me!?

 

[1997ThunderbirdLXV6]

The code will probably come back.

How soon?

 

[1997ThunderbirdLXV6]

If you are worried stop by an auto store and have the codes read again. If its going to throw the light again it will probably have a pending code set by now.

No code as of today, pending or otherwise. No check engine light. Let's hope it stays that way.

 

[1997ThunderbirdLXV6]

How many miles since you cleared the code(s)?

Ohh, I didn't pay attention to that. A bit over 50 I think.

 

[1997ThunderbirdLXV6]

Check Engine Light came back today. I just got back from a road trip, so it's been about 1,000 miles since the Light first appeared (and disappeared after I disconnected the battery).

It's the same code (P0156), and again it showed "(1/2)" after the code. I asked the guy if that meant that there were two codes total, but he appeared a bit clueless. I need to invest in my own code reader.

As before, there are no drivability issues at all (which I'm guessing is because this sensor collects information about catalytic convertor performance only, but doesn't actively influence fuel trim).

 

[1997ThunderbirdLXV6]

...another guy just checked. (1/2) is P0156 Stored; (2/2) is P0156 Pending.

 

[1997ThunderbirdLXV6]

Just from looks, does this appear to be the factory original sensor?

(Side note: that rusty shift mechanism doesn't look very confidence inspiring either.)

Buy a set for the front, and swap the current fronts to the rear.

Oh my...I need to keep this simple!

Are fronts and backs the same part? On Rockauto, some brands seem to differentiate between upstream and downstream while others don't.

 

[1997ThunderbirdLXV6]

Finally I got a little Bluetooth scanner. I used the Car Scanner app, and I'm wondering if it's poorly designed: when I look up active codes, it explains P0156 as sensor 1, not sensor 2 .

Meanwhile, I obtained this live data screen shot. Anyone can interpret this for me?

I guess my biggest question is: why does it trigger a code for the sensor, not for the catalytic converter?

 

[1997ThunderbirdLXV6]

I think first step should be switching the two downstream sensors with each other. If the code moves to Bank 1, it's clearly the sensor. If the code remains at Bank 2, I have another problem.

 

[1997ThunderbirdLXV6]

No, that *** sensor is bad, lol. Replace the
o2S2 sensor first. the others aren't pretty, but they are at least switching. O2s2 is not.

Just so we're talking about the same thing, this is the problematic one based on the code:

 

[1997ThunderbirdLXV6]

Looking at things more closely...the offending sensor (2/bank2) is different from the other three.

2/bank1

1/bank2

1/bank1

Something definitely isn't factory original...but what?

 

[1997ThunderbirdLXV6]

Funny side note: several weeks ago I posted about a rattle when in gear at a standstill.

Turns out, the connector of this O2 sensor 2/bank 2 was touching the body. The connector is attached to the transmission with a Christmas tree fastener, but there isn't sufficient clearance; as a result transmission vibration was transferred to the body right next to the driver's feet.

I'm wondering if that caused some problems for this sensor. I used a zip tie to hold the connector away from the body; rattle is gone.

Haven't changed the sensor yet, but that'll come soon. Just need to budget for parts plus the appropriate tool.

 

[1997ThunderbirdLXV6]

Monitoring the two downstream sensors, what's interesting is that when they are cold, bank 1 reads 0 volts while bank 2 (the problem sensor) reads 1.28 volts.

Once they warm up, their readings are mostly similar.

Here is a short drive today, with an interruption in the middle where I went shopping.

 

[1997ThunderbirdLXV6]

replace the fronts, move the fronts to the rear, and this all goes away.

Do you know which wire lengths I need for the V6? It seems these sensors come with different lengths wires (?).
From what I saw the other day, 1/bank 1 had a long harness with a connector all the way forward of the engine block; the others were fairly short. But I didn't measure...

 

[1997ThunderbirdLXV6]

1 ft breaker bar. The sensor doesn't move at all. I did soak it in WD40. Frankly, I'm worried to break something.

 

[1997ThunderbirdLXV6]

...another time. I'm over it for now.
The code is gone, and there's none pending since I eliminated the connector constantly hitting the body.

The scanner app also has an emissions test screen which states Catalyst "passed" (after I reset the codes). So it is getting some sort of adequate reading from that sensor.

May be better not to fix it if it ain't (entirely) broke.