Catalytic convertor warning light on

[MelbMan]

At 142k my 77TSI 2011 Polo seems to be having a series of problems. Has been parked for a while driving over the weekend quite sluggish and the catalytic convertor warning light came on in the dash. Drove home ok using a route with less hills.

Is this simply an error code you can attempt to remove. Or something more serious?

Thanks in advance.