If this warning light illuminates continuously, then you should consult your Renault dealer ASAP. The next stage logo has 'STOP' showing within this engine logo - And that does mean STOP Now!
So it could be worse.
Normally if everything is OK with the engine, this logo
lights up when you start up the engine, then goes off after a few seconds. Presumably after the engine management has found that part of the system OK.
It is monitoring the exhaust gas emissions.
Yes! A faulty
could be responsible, since a poor or no spark on one cylinder would be sending unburnt fuel to the exhaust system, that would be picked up by the sensor.
If you know someone with a system checking device,
then this will give a read out and area to repair. Or try changing a
. A favorite of mine -see Megane.
However buying spares which may not be needed
is a waste -Sadly some garages do charge heavily for
using their engine analysis equipment. My last quote for just a plug in & readout was £45.
£15 -£40 each)