Possible Cause & Correction
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Saturn SL2, 2002 Saturn SL1, 2002 Saturn SL, 2002 Saturn SC2, and 2002 Saturn SC1. However, it is still accessible from the selected car via links, so may be relevant.
Check the following items:
- Visually check vacuum hoses for splits, kinks and proper connections as shown on vehicle emission control information label.
- Check ignition wires for cracking, hardness and proper connections at spark plugs. Spray spark plug wires with a fine mist of water to check for shorts.
- Check wires for pinches, cuts and proper connections.
- Check fuel pressure. See FUEL SYSTEM PRESSURE TEST under BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
- Check for poor quality or alcohol/water contaminated fuel.
- Check for fouled spark plugs.
- Ensure the installed PCM program is correct for that particular vehicle. Check with dealer for latest application information.
- Check for a binding or sticking TP sensor. Voltage should increase steadily as throttle is moved toward Wide Open Throttle (WOT). Also check related wiring.
- Ensure PCM-controlled idle speed is correct.
- Check EGR operation.
- Check engine cooling system thermostat for proper operation and heat range.
- Check ignition control system ground and power feed circuits.
- Check canister purge system for proper operation.
- Check charging system output. Repair charging system if voltage is less than 9 volts or more than 16 volts.
- Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
- Check injector harness locations. Ensure injectors are connected to correct injector/cylinder according to firing order.
- Check for proper Crankshaft Position (CKP) and Camshaft Position (CMP) sensor resistance. Check for intermittent ignition feed or ground circuits.
- Check Heated Oxygen Sensor (HO2S) ground (corroded threads in exhaust manifold or pipe).
- Check for air leaks between Mass Airflow (MAF) sensor and throttle body.
- Check air induction system for damage, restriction or air leaks.
- Check for intake valve deposits.
- Check Manifold Absolute Pressure (MAP) and MAF sensor values and related wiring.
- Check for excessive exhaust system backpressure.
- Check for proper operation of the Transmission Fluid Pressure (TFP) manual valve switch.