Primary lambda sensor heater fault

[alackofspeed]

Hi,

My GTI's MIL came on earlier today, and VCDS reports a failed primary lambda heater. Engine is a BWA, in a 2007 running Revo Stg 1.

First problem of its kind on the car, and clearing the fault code causes it to immediately reappear.

On the MK5 if a heater problem is reported, is it genuinely a heater fault, or can it be a misleading fault?

I could replace the sensor as a first step, but at about £100 (guess) it'd be useful to know if something else maybe wrong I should investigate first.

Cheers.

[adgti]

normally if it's a lambda hearter fault it's normally failed

[alackofspeed]

TPS in the morning then.