[Ali A]

Hi, I have some issues with my car, it has now started to use more fuel than it used to. The car is modified and is decatted but there were no problems before. I decided to scan the car and the error I'm getting is this:

12A308 - Oxygen Sensor After Catalytic Converter, Dynamics, From Rich To Lean: Slow Response

Can anyone help me on this matter, I have done some research and everyone is saying different things, there is no warning light on the dashboard either as someone said there should be.

Any help would be appreciated, thanks in advance.

[Ali A]

Can anyone help?

[Brandoch]

Originally Posted by Ali A

Can anyone help?

Maybe post in the F20 1 series forum, you will get better results.

[No one]

A sensor might seem retarded because you are going too fast: say, if your decatted car when going with the headlights on leaves the light they throw behind, that's a tad too fast, you might need to slow down.

More seriously and apparently (a wild guess), the sensor might have degraded because of decatting and you need to replace it, perhaps with a stub.

[M2siast]

My guess is that your car is simply in limp mode because of the absence of cats.