[DoZZa]

Hi all,

I have to go on a long journey today as I am going to my grandmothers funeral. 🥹

My OG M2 has just lit up the CEL. I checked the codes and it's showing the following.

12B304 - Lambda probe heating after catalytic converter, control: Open Circuit

I cleared the codes, drove the car for a bit, and it's come back.
The car is driving fine, performance is fine, and it doesn't smell like it's running rich.

No work has been done on the car recently, so don't think it's a lose connector or something similar.

The car is running bm3 Stage 2+, so catless.

Question is, is it OK to drive?

It's just typical that my other car, a Subaru Forster, stripped 3rd gear a couple of days ago. So that's not an option to drive either!

Not worried about fuel consumption if that is the only issues with a broken sensor. Just worried that it could damage the engine in some way.

Help please 😊

[annabellapizza]

Yes its just an error code, youre fine. Sorry for your loss, Stop worrying and just continue driving normally.

[DoZZa]

Originally Posted by annabellapizza

Yes its just an error code, youre fine. Sorry for your loss, Stop worrying and just continue driving normally.

Thanks, I had no choice but to drive the car.

I cleared fault codes before the long journey, CEL came back on after stopping for fuel.

Cleared them again as the CEL was annoying me!

It has not come back since! So, whatever it was, it seemed to have sorted itself out.

[RockCrusher]

Originally Posted by DoZZa

Hi all,

I have to go on a long journey today as I am going to my grandmothers funeral. 🥹

My OG M2 has just lit up the CEL. I checked the codes and it's showing the following.

12B304 - Lambda probe heating after catalytic converter, control: Open Circuit

I cleared the codes, drove the car for a bit, and it's come back.
The car is driving fine, performance is fine, and it doesn't smell like it's running rich.

No work has been done on the car recently, so don't think it's a lose connector or something similar.

The car is running bm3 Stage 2+, so catless.

Question is, is it OK to drive?

It's just typical that my other car, a Subaru Forster, stripped 3rd gear a couple of days ago. So that's not an option to drive either!

Not worried about fuel consumption if that is the only issues with a broken sensor. Just worried that it could damage the engine in some way.

Help please 😊

It is my SOP to not set out on a long road trip with a car manifesting a known problem.

There is nothing like hundreds of miles between you and the nearest dealer to have a seemingly benign problem turn into the need to flat bed the car to the dealer for repairs.

I will admit in my 996 Porsche Turbo after driving from MO to Barstow CA upon restart after filling the gas tank the CEL came on. I forget the error code but it was a problem with an O2 sensor heater circuit.

The engine felt fine.

I cleared the code and headed north towards home some several hundred miles away. About half way there stopped for gas. Upon engine restart CEL on again. Same code. Cleared it. Drove on.

Made it home with no drama. As soon as I could got the car in and had all 4 O2 sensors replaced. Oh, car had 132K miles on it. With new sensors engine ran better.

But on the way home I was prepared to if the engine started acting up in any way to pull mover and call my auto club.

So the short version is the car/engine will probably be ok. But no guarantees. And like me I think you have to be prepared to if the engine manifests any signs of distress you need to pull over when safe and have the car flat bedded in to have the problem sorted.

Sorry about your dear grandmother.

[///M TOWN]

It sounds like you got some bad fuel and now you have a bad O2 sensor accordingly

[SchnellerM2C]

The code "12B304 - Lambda probe heating after catalytic converter, control: Open Circuit" relates to an after CAT O2 sensor whose heater circuit is defective. As this sensor only monitors the efficiency of the CAT converter, it isn't involved in regulating fuel mixture on a particular bank of cylinders.

So, it's OK to drive.
As you have no CATs to begin with, I would expect that there must be a provision in your tune that causes the DME to ignore the after CAT O2 signals.
However, the heater circuit for the O2s appears to still be monitored.