Exhasut Fume light

[DeepM1989]

The exhaust fume light is constantly staying on, the thing is; it comes on sometimes and other times disapperas, do yuo guys know what the cause could be? A garage said it could be the fan belt, does this sound right? Any help would be appreciated.

Deep

[chewy]

Lamba sensor if the lights on and not flashing.

The light will come on and stay on for 14 engine starts then be back on in another 8 or so.