CBEA deleted random p0136 cel

[PickleRick]

Cel is for the O2, I may be wrong but the two remaining exhaust sensors, one in manifold and other in the down pipe are egt sensors. Still has asv but EGR and dpf are tuned out of the equation. Still stock power tune, no stage to it. Even the DSG tune was left alone.

I was thinking the O2 sensors were all post dpf with us non existent on this off road only vehicle.

Been running about 3,000 miles post delete off road only with not so much as a hickup or cel. I ran a scan, did some logs and everything looked good. Deleted and hasn't come back.

The day it came on was after/during several inches of heavy rain. Not sure if related.

No signs of boost leaks. No noticable loss of power.

I don't want to throw two new sensors at if if she doesn't need it but at the same time I realize how fragile the common rail is and don't want to push my luck by neglecting it.

Thanks ahead of time.

 

[TurboABA]

Post scan\code with all FF data... lots of details you're potentially not looking at.

 

[oilhammer]

The upstream oxygen sensor is still used on deleted cars... however, HOW it is used is at the discretion of the tuner... you would have to ask them on that. Some earlier deletes also retained the orange EGT up there as well, but the later ones don't. I guess they figured that sensor was redundant, as there is already an EGT sensor in the turbocharger itself.

 

[PickleRick]

I had the tuner lined up before the delete to make sure everything was in order before dropping it off to him and I believe the colors of both remaining sensors he told me to keep were the orange and I think brown (could be black as dark brown/black look the same to me).

So just to verify the orange plug sensor (would be post turbo and pre dpf) is an O2?

If so I'll check to make sure it's not rubbing against anything and doubled check the plug end. I'll also try to get a scan this weekend.

 

[oilhammer]

No...

Two EGTs in the top of the DPF/DOC assembly, an orange and a brown. Then the oxygen sensor, which has a big black connector.

What specific DTC do you have? Like I said, normally the only sensor left in place when a delete is done on the CBEA/CJAA/CKRA is the upstream oxygen sensor.

 

[TurboABA]

If you won't share the scan and logs, we don't know what the actual issue is.
The code typically points to an electrical short, but if could also indicate a dead sensor.
Logging the sensor values would flush out the suspected problem, potential wire short, etc.

 

[TurboABA]

 

[PickleRick]

I'm not at the car to do a scan. The BHW powered yota is my daily. I won't have access to the car and laptop at the same time until Friday or Saturday.

The code was p0136 bank 1 sensor 2. If this was a V8 rwd/4wd it would be drivers side secondary. Unfortunately with an inline 4 i have no idea what it would be. Neither sensor left in this looks like an O2 to me, the little lady drives a disco 2, I'm unfortunately very familiar with O2 sensors and using a scanner to find a dead one.

And you are correct, I only have two sensors left, the one immediately post turbo in the down pipe and the one in the back of the turbo manifold. That's it for exhaust sensors. The rest are empty connectors.

No big connectors, just the brown and orange. I found it odd egt sensors could potentially toss an O2 code. The common rail is still a learning curve for me.

 

[TurboABA]

Knowing just the code as per above is insufficient to pinpoint anything.
You also keep talking\switching between EGT sensor and O2 sensor which your code is for.
What are you referencing when you say "exhaust sensor"?

 

[oilhammer]

A deleted car has no downstream oxygen sensor.

You need to contact the tuner...

 

[TurboABA]

Pick a number... any number

 

[PickleRick]

Number 10 and number 12

 

[PickleRick]

Knowing just the code as per above is insufficient to pinpoint anything.
You also keep talking\switching between EGT sensor and O2 sensor which your code is for.
What are you referencing when you say "exhaust sensor"?

I'm referencing any sensor plugged into the exhaust system.

 

[TurboABA]

I'm referencing any sensor plugged into the exhaust system.

Thanks for clarifying that you're not actually talking about the sensor related to the DTC..... just any sensor in the exhaust system.

 

[TurboABA]

Number 10 and number 12

Neither of those is related to your code, so go ahead and read all the stuff that's been suggested above.

 

[oilhammer]

I've already explained it, but I will try again... and maybe that picture will help.

#10 is the EGT sensor in the turbo.

#12 is the upstream oxygen sensor.

BOTH of those get retained when a delete is done. Literally every other part in the entire exhaust system that has an electrical connector on it, including the downstream oxygen sensor, goes away.

If you have a DTC related to a sensor that is no longer present, you need to contact the tuner. You may also want to check the car side connector (in this case, under the shield on the right middle of the car) to see if the wires were not properly covered and secured when the delete was done, and maybe something is rubbing through...

 

[PickleRick]

Do you by chance know if vw considers the oxygen sensor #12 the bank one sensor 2?

I'll also check the empty sensor plugs, I zip tied them under the heat shield but if she hit something in the road, it's possible to damage one of them. The S model sits low to the ground.

 

[oilhammer]

They do not. The industry standard is #1 is upstream, #2 is downstream. And "bank 1" will always be the one with #1 cylinder. In most cases, any inline 4 cylinder will JUST have bank 1, because it only has one bank (obviously). However, in some cases, you'll see an inline 4 that has divorced exhaust manifolds, each with their own upstream sensor, in which case they would label the pair withOUT #1 cylinder as Bank 2. That is more common with inline 6 cylinders, though.

In some cases, there may still be a modulated 12v feed to the oxygen sensor heater, which is why a potentially damaged wire harness to that connector could cause a problem. The tuners would/should know this, and would/should know if they wrote that portion out of the flash file.

Given that you drove the car 3000 miles post-delete with no MIL flagged, I suspect it could be something of that nature.

 

[TurboABA]

Do you by chance know if vw considers the oxygen sensor #12 the bank one sensor 2?

Only someone who would start counting from the tail pipe could come up with that nomenclature

 

[PickleRick]

Only someone who would start counting from the tail pipe could come up with that nomenclature

The reason behind it is the 4 cylinder only has one bank, meaning every sensor is a bank one sensor. The sensor #12 in question also happened to be the 2nd sensor from the engine if counting all the sensors in their original location going from engine towards tail pipe.

 

[TurboABA]

The reason behind it is the 4 cylinder only has one bank, meaning every sensor is a bank one sensor. The sensor #12 in question also happened to be the 2nd sensor from the engine if counting all the sensors in their original location going from engine towards tail pipe.

It might be the 2nd "exhaust sensor" from the engine as per your nomenclature, but the DTC is for a 2nd oxygen sensor, which would translate to 6th exhaust sensor using your approach\terminology!

 

[PickleRick]

I'm not sure where you got 6th, but now that I know the cel is for a secondary O2 down stream sensor and my #12 plug in is the #1 upstream I'm better able to run diagnostics.

 

[oilhammer]

Because it is normally the 6th sensor in the exhaust system.

EGT sensor in the turbo (1)

upstream oxygen (2)

two EGTs in the DPF/DOC upper (3 &4)

EGT in the DPF downpipe (5)

downstream oxygen (6)

... there's also two delta pressure sensors, the EGR cooler outlet temp sensor, the integral position sensor in the exhaust flap.

With a delete, most of that is either gone or in the case of the EGR cooler temp sensor, simply ignored.

 

[TurboABA]

I'm not sure where you got 6th

Use two hands if you run out of fingers when trying to get there

 

[PickleRick]

And just so we are completely clear, in the picture shown, sensor number 6 would be bank one sensor 2 oxygen sensor?

In my Google search this question wasn't answered in any of the threads I've come across specifically pertaining to p0136 cel. It might help others searching this in the future.

 

[oilhammer]

Yes, that is bank 1 sensor 2 oxygen sensor.