Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Try cleaning the throttle body. Remove the air intake tube from the front of the engine and use a throttle body cleaner spray (or carburetor cleaner spray) to clean the throttle blade and bore. With the key off, open the throttle blade by hand to fully clean the area. This should allow more airflow at closed throttle and help to stabilize the idle.
No need to disconnect the battery. Just make sure the key is OFF. Also make sure the K&N air filter is not over oiled. If it is, it can coat the mass airflow sensor and cause driveability issues.