40d Intermittent pre cat fault code
 

Hi,

x5 40d (35d in the US I think!) with a fault code that comes back after clearing.

287500 Oxygen sensor before catalytic converter, signal: Too low the event of coasting overrun.

Car drives fine and no faults on dash. No other related faults stored. Shows up as intermittent fault so not permanent.

My initial thoughts are a sensor on the way out or dirty.

Any thoughts on this or recommendations to try?

Just for info if anyone else gets this issue, a new pre cat o2 sensor stopped the fault returning and also gained a small improvement in MPG.