Hyundai's have a learning ECU so will revert back to Factory setting's in time so reset your ECU
Firstly bring the car to normal operating temperature by
driving for 15 minutes or so.
Now open the bonnet and disconnect the earth lead from the
battery, ensure this is not touching any part of the bodywork - insulate if necessary - and wait 5 minutes.
Next depress the foot brake for 20 seconds - this will completely discharge the ECU's
capacitorsvia the
brake lights.
The next step (to be carried out immediately, while the engine is still warmed-up) is to carefully re-connect the
battery earth lead, close the
bonnet and now drive the car in a spirited fashion (accelerating rapidly through the gears, full-throttle straights etc. etc.) for a full 30 minutes. Try to choose a quiet time on the roads for this, (i.e. early on a Sunday morning!).
This period of driving will `re-educate` your ECU into adopting more aggressive timing curves and alter the fueling to match. It will also allow the unit to recognize any modifications you have made and to react accordingly.
If, on the other hand, you are not interested in outright performance, but are more concerned with economy and flexibility, use your normal driving style during this 30-minute run!.
Over time, the ECU will slowly revert to the factory settings......especially if it is not being driven `spiritedly` on a regular basis.
Accordingly, many owners tend to do this reset monthly, or before a track day or even a long run.