Poor Fuel Economy
- Check non-engine related factors. Check tire pressure, dragging brakes, transmission problem, driving habits, etc.
- Check for vacuum leaks.
- Perform QUICK TEST. See TESTS W/CODES - 2.5L article.
- Check ignition system. See CIRCUIT TEST JB in TESTS W/CODES - 2.5L article.
- Check fuel delivery system. See CIRCUIT TEST HC in TESTS W/CODES - 2.5L article.
- Check exhaust system. See CIRCUIT TEST HF in TESTS W/CODES - 2.5L article.
- Check EGR system. See CIRCUIT TEST HE in TESTS W/CODES - 2.5L article.
- Check engine compression. Check engine mechanical condition. Check intake manifold, manifold gasket, camshaft and valves.
- Check cooling system thermostat.
- Check for slipping clutch.
- Check odometer calibration.
- Vehicle load, driving habits, road and weather conditions can also effect fuel economy.