AFR stuck at 14.85 - HELP

[Jeff23spl]

The rear sensor is a narrow band and use just 1 wire as a signal with ground and the other 2, are the heater element. (4 totals more with black, grey white)

The front is a wideband using more wires just for sensing and it use 2 different connectors at the probe connection itself. I can see at least 6 wires in your document....(I tough it was 5 but it could be 6 also...) (those are a bit more colored)

If you remove the battery tray, you will have access to both side of the connector a bit more easily. (the bracket is above the rear of the trans) You may even just follow the color code on the same side of the harness.

Unfortunately, it is hard to figure out the signal out of a wide band sensor with a multi meter, you better check continuity back to the ECM and inspect each pin to make sure there is no issue there.

[Witness]

So I got home from work and removed the battery and tray. I found this; one red and white wire is completely out of the connector as shown in the picture. Is there a way do take apart the connector to solder the wire back on or how would I go about doing this repair?

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[danb]

[QUOTE=Witness;3173151]So I got home from work and removed the battery and tray. I found this; one red and white wire is completely out of the connector as shown in the picture. Is there a way do take apart the connector to solder the wire back on or how would I go about doing this repair?



Maybe source another harness and scavenge the section thats bad and re solder it together.... If not then I would remove it and try to cut down the plug to get to it and solder on a jumper wire for each wire, making it a little longer and re solder it back in. And use something to help seal the new connections

[Jeff23spl]

glad you found it. As stated above, i would source a used connector and replace it by soldering the wires and using heatshrink with glue to isolate the connection (need to be put before soldering )

I assume it is the one on the car side not the probe ? On the probe, you may have your old probe connector ?

I would double check and compare with the used one but i remember my 2006 2.0l GS was also using a wideband so maybe you may find it on a non speed model but don't blame me if not, it was a long time ago....

At worst, if you are very handy, you may take a picture for references and try to unlock the pins with a small screw driver and solder back an extension wire on it then put it back. But sometimes, the pin won't hold tight after and if you never played with that, good chances that you create more problems....(You may also try to solder a wire directly on the broken pin without removing it from the connector but it would be even harder to make a safe connection...This is a recipe for further problems if you don't do it perfectly.

[Witness]

Originally Posted by Jeff23spl glad you found it. As stated above, i would source a used connector and replace it by soldering the wires and using heatshrink with glue to isolate the connection (need to be put before soldering ) I assume it is the one on the car side not the probe ? On the probe, you may have your old probe connector ? I would double check and compare with the used one but i remember my 2006 2.0l GS was also using a wideband so maybe you may find it on a non speed model but don't blame me if not, it was a long time ago.... At worst, if you are very handy, you may take a picture for references and try to unlock the pins with a small screw driver and solder back an extension wire on it then put it back. But sometimes, the pin won't hold tight after and if you never played with that, good chances that you create more problems....(You may also try to solder a wire directly on the broken pin without removing it from the connector but it would be even harder to make a safe connection...This is a recipe for further problems if you don't do it perfectly.

I'm pretty handy, I build racing drones as a hobby.

So you're saying theres a way to take apart the connector so I could solder the wire back to the pin? Because I really dont feel like spending that much money to buy another harness just for a connector.

[Jeff23spl]

of course i wouldn,t replace or bought the complete harness, i would personally go to a selfservice junkyard with my old connector and snick into mazda model 06-09 to find one identical and i would cut that specific connector with 6-12inch of wires.

But each connector pins has a locking leg against a plastic bump, you need to push that leg in to be able to push the pin out of the connector. I bet Youtube is full of video about this. i would cut the other wires off the connector to work on it out of the car and solder it back....just keep lenght of wires on both side to make it easy to connect back...

[Vansquish]

I'm sure you can solder or re-pin that connector. That is a (relatively speaking) trivial part that only causes the engine to run out of stoich. By contrast, I re-pinned/soldered one of the leads to my ignition coil on Cyl 3 a couple of years ago. It's still working fine nearly 20k miles later.

[Witness]

Originally Posted by Vansquish I'm sure you can solder or re-pin that connector. That is a (relatively speaking) trivial part that only causes the engine to run out of stoich. By contrast, I re-pinned/soldered one of the leads to my ignition coil on Cyl 3 a couple of years ago. It's still working fine nearly 20k miles later.

So you're saying that the red/white wire wont fix the problem I have with my O2 sensor not working?

[Vansquish]

@Witness; I'm not sure where you're getting any negativity in my previous response. I don't think I said that at all.

The point I was making is that I tried exactly what you are suggesting fixing on a much less trivial part, and it is still working to this day. That is, you can certainly try and re-pin/solder the loose wires into the plug. I did the same thing on my coil pack for cylinder #3 , and haven't had any trouble with it since.

[Witness]

The plug is a solid piece of plastic, no way to take it apart. So I clipped the plug off of the harness side, and clipped the plug off of the O2 sensor side and soldered (temporarily) the wires directly to each other to see if that fixes the problem.

The AFR stayed at 14.85 for a bit, then pegged at 14.99, quickly jumped to somewhere around 15, then pegged at 29. I was getting very sporadic readings. I shut the car off and tried again. The same thing happened.

Still have no idea what it is. Maybe the primary O2 sensor is bad from the couple of times I drove the car running rich? I was getting a code for sensor 2 no activity but idk if that causes the sporadic readings I was getting.

[Vansquish]

Interesting. Are you sure you soldered the correct wires together?

[Jeff23spl]

did you wait long enough to have the probe to heat up enough ? (probably few minutes)

Can you run the car a bit to make some air flow, your fuel trim memory are probably still expecting a bad signal.....

[Witness]

Originally Posted by Vansquish Interesting. Are you sure you soldered the correct wires together?

Before I clipped the wires I marked them with tape cause I knew them being the same colors would be a problem. But just to make sure I resoldered them in the different order. The afr pegged at 14.85 with no change. So I soldered them back how it was before.

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Originally Posted by Jeff23spl did you wait long enough to have the probe to heat up enough ? (probably few minutes) Can you run the car a bit to make some air flow, your fuel trim memory are probably still expecting a bad signal.....

Turns out this was the problem. The LTFT history and the probe needing to heat up, the afr slowly stabilized. I'll post some logs

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[Witness]

Here are some datalogs at idle and driving normally. I didn't do any pulls as I'm not sure if my cars is 100% yet.

Hopefully everything is okay but if anyone sees anything in the logs lmk

[tegxsi]

Logs look alright...
If the car feels normal then I think it's safe to do pull.