Hyundai SX2 Owner's Manual page 646

Maintenance
The Petrol Particulate Filter (GPF) lamp
stops illuminating, when the driving
speed exceeds 50 mph (80 km/h) with
engine RPM 1,500-4,000 and the gear in
the 3rd position or above for about 30
minutes.
When the GPF lamp starts to blink or the
warning message "Check exhaust
system" pops up even though the vehicle
was driven as mentioned above, we
recommend that you have the GPF
system checked by a HYUNDAI
authorised repairer.
With GPF lamp blinking for an extended
period of time, it may damage the GPF
system and lower the fuel economy.
CAUTION
We recommend you to use only the
regulated petrol fuels, when your vehicle
is equipped with the GPF system.
When you use other petrol fuels which
contain unspecified additives, they may
damage the GPF system and cause
exhaust emission problems.
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