Clean the throttle body with some approved cleaner from your local parts store then perform the following relearn procedure when done and your problem should be taken care of. You can also get some approved cleaner to clean the mass airflow sensor, let me know if you have questions. Thanks
1. Perform a Throttle Learn. 2. Start and idle the engine in PARK for 3 minutes. 3. With a scan tool, monitor desired and actual RPM. 4. The Electronic Control Module (ECM) will start to learn the new idle cells and Desired RPM should start to decrease. 5. Ignition OFF for 60 seconds. 6. Start and idle the engine in PARK for 3 minutes. 7. After the 3 minute run time the engine should be idling normal. Important. 8. If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations and extended idles. 9. After the drive cycle, the engine should be idling normally. 10. If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 6.