Sensor/System Checks

Use a scan tool to monitor the Knock Sensor (KS) system for excessive spark retard activity.
Check for throttle body tampering, excessive deposits, or damage.
Check the Throttle Position (TP) sensor and related circuits. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 2.2L SATURN "L" SERIES article.
Check the Positive Crankcase Ventilation (PCV) system for proper operation. See POSITIVE CRANKCASE VENTILATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTS - 2.2L SATURN "L" SERIES article.