Bmw f650gs single spark lamda sensor

[Pvk]

Hi all
My single spark lamda senor graph on gs911 hardly fluctuates . Bike blows out black smoke and uses lots of fuel. Plug is fowled . Had one error reported that lamda heating element  failure . Do i just replace sensor or check further.  Many thanks in advance

[WayneC]

Replacement of Lamda does sound appropriate, they have usable life of around 120,000 km but am aware of failures before that

[Pvk]

Many thanks
Take it easy down under