Which Lambda sensor?

[johnny2007]

Hi everyone,
This is one for the good mechanics here i.e. @carmanmemoranda @Mottie etc.

Audi A3 2006 1.6 8V sportback petrol manual.
One of the O2 sensors has gone bad.
A scan indicates the following:

O2 sensor negative current control circuit bank 1 sensor bank 1 open

Is it the pre cat or after cat?

Also, don't know if relevant but the following codes are there and can't be deleted, even temporarily:

P0380 glow plug/heater circuit A

P0780 shift error

What brand of O2 sensor do you recommend bearing in mind that the car is 20 years old and won't need to last forever?
In other words, are the cheap ones ok?
I see Ridex on Autodoc.
Thanks

 

[Mottie]

This is one for the good mechanics here i.e. @Mottie etc.

That’s me out of it then…I'm retired now but even when I was working, I’ve never replaced one of them in my life!

 

[Jurassicspark]

O2 sensor negative current control circuit bank 1 sensor bank 1 open

That's referring if you've got a V engine and it tells you which side it is.

Is it the pre cat or after cat?

That's just telling which bank the sensor is on. You need to know whether if its "sensor one or sensor two" Which scanner are you using?

Also, don't know if relevant but the following codes are there and can't be deleted, even temporarily:

P0380 glow plug/heater circuit A

P0780 shift error

Pending codes?

What brand of O2 sensor do you recommend bearing in mind that the car is 20 years old and won't need to last forever?
In other words, are the cheap ones ok?

NTK or bosch.

 

[Jurassicspark]

O2 sensor negative current control circuit bank 1 sensor bank 1 open

Negative current, I think that would be referring to a ground circuit. Before chucking in a new sensor check the wires to it. Oxygen sensors last for quite a long time (if your air/fuel mixture is on the right parameters.) A quick resistance check would rule out if the problem is the sensor.

 

[johnny2007]

That's referring if you've got a V engine and it tells you which side it is.

That's just telling which bank the sensor is on. You need to know whether if its "sensor one or sensor two" Which scanner are you using?

Pending codes?

NTK or bosch.

It's a straight 4 cylinder engine 1.6l 8 valves.
Using vcds lite.
There are only 2 sensors on this car, one at the end of the exhaust manifold, before the cat, another one just past the cat.

 

[Jurassicspark]

There are only 2 sensors on this car, one at the end of the exhaust manifold, before the cat, another one just past the cat.

Upstream. Before replacing it check the wires to it.

 

[Belle427]

Pre cat sensor, check wiring first as suggested.
If you do replace it only fit genuine or equivalent not unbranded.

 

[carmanmemoranda]

Bank 1 is relevant if v engine etc, but if straight 4 it's just them 4.

Sensor 1 is precat
Sensor 2 is after cat.

Ngk (or ntk) always, or main dealer (likely ntk or bosch). Never. Never Never use a universal or a cheapy

 

[carmanmemoranda]

Looking at this now I've got a few more minutes.

P0380 might be a temporary or permanent code. Delete it, see if it returns. But likely an injector beginning to fail.

P0780. I've no experience of. Again, delete it, see if it returns 1st

If it doesn't delete, any, or what symptoms have you got?

 

[johnny2007]

Thanks for the info guys.
Regarding the other 2 codes, they can't be deleted and I have no issues.
In fact, the gearbox/clutch is the smoothest I've ever used.
Possibly there's a new clutch on this car but it's not in the service book.
I only had it since August last year.

 

[carmanmemoranda]

Thanks for the info guys.
Regarding the other 2 codes, they can't be deleted and I have no issues.
In fact, the gearbox/clutch is the smoothest I've ever used.
Possibly there's a new clutch on this car but it's not in the service book.
I only had it since August last year.

I assume they are just codes and not putting the eml light on?

Just ignore if no issues. Lots of cars have hidden codes that affect nothing

 

[carmanmemoranda]

The only caveat.

Just be aware if it is an injector issue starting. Get if checked out sooner rather than later if any symptoms of under or over fuelling, or misfiring, power issues etc

 

[johnny2007]

Next problem please:
The sensor is in a bitchh position, so to make my life easier I bought the special tool (picture attached)
But, there are pipes in the way and, unless I'm mistaken, they are AC pipes that cannot be disconnected to access the sensor.
Or am I wrong? (I hope I am)
Could I loosen one of those pipes) possibly undoing the bolts in the last picture?
Thanks

 

[carmanmemoranda]

Sorry to say. There are other tools available which should give you access.

Be warned, if its very tight, its easy to strip the threads in the exhaust!!!

 

[johnny2007]

Sorry to say. There are other tools available which should give you access.

Be warned, if its very tight, its easy to strip the threads in the exhaust!!!

Yes, I've seen a few pictures online.
I've been spraying wd40 every day for a week now, so hopefully it will just come out nicely.
I found this tool:

Hilka Pro-Craft Oxygen Sensor Wrench - Screwfix

Order online at Screwfix.com. For quick removal or replacement of Oxygen Sensors. Offset drive with wire gate accesses sensor from the side, preventing damage to wire harnesses. Suitable for heated and unheated oxygen sensors. Star shaped socket for accessibility fits standard wrench. FREE next...

www.screwfix.com

And this:

https://www.amazon.co.uk/Mekaink-Oxygen-Sensor-Flex-Wrench/dp/B07DW2P11F/ref=pd_aw_ci_mcx_mh_mcx_views_0?pd_rd_w=MU3lH&content-id=amzn1.sym.42c045e2-bd09-44b6-b445-e4140e05d91f%3Aamzn1.symc.acfafb1d-071f-4fdf-beff-aca206a47be9&pf_rd_p=42c045e2-bd09-44b6-b445-e4140e05d91f&pf_rd_r=SGSYKPDPHWTXP2VHFS5J&pd_rd_wg=9nmnk&pd_rd_r=957da320-c46b-46e9-84a2-34660aded69e&pd_rd_i=B07DW2P11F

Which one would you recommend?

Thanks