Check Engine Light illumination—combined with a lack of power or a stumble on acceleration—may be caused by the throttle position switch (TPS). Kia released an improved part which should correct this concern.
Car Problem Reports
Kia Sportage Faulty Throttle Position Switch
Kia Sportage Problem
Exhaust & Emissions Affected: 2.7L V6
Average Mileage: 58,956 mi (27,000 mi - 87,600 mi)