[335inYEG]

BRAINSTORM SESH & GO!

2010 N54 e92

I was changing the OFHG at 3 am (Yes i know i shouldn't be doing car work when you're tired but it was the only time i had free) now i'm paying the price...

When i was putting everything together i pinched the harness that connects to the bank 2 oxygen sensor...
see photos
Immediately after pinching the wire the car wouldn't even run properly since it thinks the 02 sensor is'nt connected

To fix this, i spliced in a 14g wire and ever since then the bank 2 oxygen sensor never read correctly and always threw a code..
i replaced BOTH pre and post cat bank 2 oxygen sensor with OEM to rule out bad sensors and i still get multiple oxygen sensor codes (See photo)


I would LOVE to replace that harness that i pinched but looking at realoem its part of the whole main harness

What can i do guys???
I've talked to enthusiasts locally and they said i'm out of luck since the resistance of the wire will always be different after splicing in a wire.
Others say there must be a way to fix this without replacing the whole main harness.

[335inYEG]

Bump?

[RocketSurgeon]

When you say that you spliced the wires, did you solder them? How did you reconnect the wires? I'm pretty confident that the wires can be repaired

[335inYEG]

Hey RocketSurgeon,


I used 16 gauge copper primary wire with 2 butt connectors

Tested it on my ohm meter, inserted the positive and negative needles into each side of the butt connectors and it reads 0.08 ohm's, although i'm not sure what that means.

I also have 18 gauge copper primary wire if that would make things any better?

[RSL]

Widebands take precision readings and work with minute changes in voltage. I'm under the impression that they are tuned with resistors in the connector when built. Even if they're not, crimp connectors are crappy joints and adding wire both change the voltage drop on the wires, which changes the signal. Seems obvious it changed enough or added enough resistance to be out of spec and/or make the DME aware of it and/or one of your crimps isn't making good contact.

Suck it up and buy a new sensor or at least remove the additional wire and solder the original wire ends together. There's real no guarantee that will work well enough either, but would be your best shot...probably easier/faster/more reliable to just buy a new one.

[RocketSurgeon]

Solder and heat shrink is the only way to go here. You really need it to be solid and water tight.
0.08ohms isn't much resistance, but it's still about 40 times the resistance of an equal length of copper wire.

[335inYEG]

Originally Posted by RSL

Widebands take precision readings and work with minute changes in voltage. I'm under the impression that they are tuned with resistors in the connector when built. Even if they're not, crimp connectors are crappy joints and adding wire both change the voltage drop on the wires, which changes the signal. Seems obvious it changed enough or added enough resistance to be out of spec and/or make the DME aware of it and/or one of your crimps isn't making good contact.

Suck it up and buy a new sensor or at least remove the additional wire and solder the original wire ends together. There's real no guarantee that will work well enough either, but would be your best shot...probably easier/faster/more reliable to just buy a new one.

You seemed to misunderstand .... i did buy new sensors. The wire isnt broken on the sensor side its broken on the main harness side.
Understand my dilemma now?

[335inYEG]

Originally Posted by RocketSurgeon

Solder and heat shrink is the only way to go here. You really need it to be solid and water tight.
0.08ohms isn't much resistance, but it's still about 40 times the resistance of an equal length of copper wire.

Hmm okay thank you so much RocketSurgeon It's unfortunate there is no other means of fixing an issue like this.
The new one i made i used heat shrink and 18 gauge wire.

Found out also the previous owner installed the downpipe fix into the ecu while running MHD, that may have contributed into the whole error codes?

[RSL]

Originally Posted by RocketSurgeon

Solder and heat shrink is the only way to go here. You really need it to be solid and water tight.
0.08ohms isn't much resistance, but it's still about 40 times the resistance of an equal length of copper wire.

It's not a lot in the grand scheme, but may be significant at the scale it's used in. The connectors are probably worse than the extra few inches of wire either way.

Originally Posted by 335inYEG

You seemed to misunderstand .... i did buy new sensors. The wire isnt broken on the sensor side its broken on the main harness side.
Understand my dilemma now?

Yikes, yeah, missed it was to the main harness. Yep, solder, heat shrink and hope for the best. I'd still lose the extra wire that adds length and a second joint if at all possible though.

Aren't DP fixes installed on the secondary O2s?

[335inYEG]

Sure enough i opened up the ECU box and found this.. while running MDH i believe this was the root of my problem. Time will tell now but in the meantime selling a BMS DP FIX V3

Originally Posted by RSL

It's not a lot in the grand scheme, but may be significant at the scale it's used in. The connectors are probably worse than the extra few inches of wire either way.

Yikes, yeah, missed it was to the main harness. Yep, solder, heat shrink and hope for the best. I'd still lose the extra wire that adds length and a second joint if at all possible though.

Aren't DP fixes installed on the secondary O2s?

[RSL]

At least it was something that just needed to be taken out and not replaced $$$

[335inYEG]

Originally Posted by RSL

At least it was something that just needed to be taken out and not replaced $$$

This was after i replaced both pre and post cat bank 2 02 sensors hahaha

[RSL]

When I do stuff like that, I tell myself it needed to be replaced soon anyway...whether it did or not lol

[droptop335i]

Originally Posted by 335inYEG

BRAINSTORM SESH & GO!

2010 N54 e92

I was changing the OFHG at 3 am (Yes i know i shouldn't be doing car work when you're tired but it was the only time i had free) now i'm paying the price...

When i was putting everything together i pinched the harness that connects to the bank 2 oxygen sensor...
see photos
Immediately after pinching the wire the car wouldn't even run properly since it thinks the 02 sensor is'nt connected

To fix this, i spliced in a 14g wire and ever since then the bank 2 oxygen sensor never read correctly and always threw a code..
i replaced BOTH pre and post cat bank 2 oxygen sensor with OEM to rule out bad sensors and i still get multiple oxygen sensor codes (See photo)


I would LOVE to replace that harness that i pinched but looking at realoem its part of the whole main harness

What can i do guys???
I've talked to enthusiasts locally and they said i'm out of luck since the resistance of the wire will always be different after splicing in a wire.
Others say there must be a way to fix this without replacing the whole main harness.

Help guys! I got the same codes when installing a metal intake manifold. I found the same wiring damaged and opened it up and just the single yellow wire was cut. I connected it with a t-clip connector but the codes still come back although a bit later

[BSM n54iS]

Originally Posted by droptop335i

Help guys! I got the same codes when installing a metal intake manifold. I found the same wiring damaged and opened it up and just the single yellow wire was cut. I connected it with a t-clip connector but the codes still come back although a bit later

Didn't you read above splicing in a different connector will change the resistance and voltage reading. I'd recommend taking out the connector and try to twist the copper around themselves again or solder.

[e90tt335i]

I am having the same issue, one of my wires from the actual harness was ripped, I connected in a new wire of similar gauge and I am getting a P0139 code (02 sensor circuit slow response). I simply twisted a new wire on and taped it up, not sure if I need to solder it or make sure to use the exact same gauge?