Whilst driving along the motorway yesterday the Exhaust Emission Warning Light (looks like an engine glowing orange in the middle of the speedo display) came on.

In a bit of a panic when any warning light comes on I stopped and checked the owners manual(page 86 & 147), which says:-

Control indicator

for exhaust

Illuminates when the ignition is switched on
and during the start attempt. Goes off
shortly after the engine starts running.
If it illuminates while the engine is running,
it indicates a fault in the emission control
system. The permitted exhaust values may
be exceeded. Seek the immediate
assistance of a w ork shop.

Obviously this is impossible while on a motorway, but how urgent does this need to be looked at by a garage.

I need the car everyday leading upto Christmas so what am I suppose to do?

Just how bad is it to drive with this warning light on?

I did the pedal test and it came up with two fault codes 0115 and 571 (I tried it a few times as the flashing is pretty quick) the first one according to the fault code posting on the sticky refers to the Engine Coolant temperature, which I am pretty certain refers to the fact that my thermostat is not working correctly. But I cannot find any reference to the other code.

The car seems to be running smoothly in fact I think my petrol consumption has improved since the fault light came on.
Any ideas please