1994 Chevrolet Blazer Owner's Manual - Page 274

Exhaust System 'Tohelp prevent damage to your exhaust system, do not continue to drive your vehicle if you notice: Engine misfiring Loss of performance 0 Other unusual operating conditions Have your engine and exhaust system serviced regularly. Three- WayCatalytic Converter Your vehicle's three-way catalytic converter is designed to reduce the pollutants in your vehicle's exhaust. Use only unleaded fuel in your vehicle. If you use leaded fuel, you could damage your three-way catalytic converter and other engine components. Engine Control Module System This system has an oxygen (02) sensor that helps keep your engine's air-fuel mixture at a proper level. Use onlyunleaded fuel in your vehicle. If you use leaded fuel, you could damage your oxygen (02) sensor and affect your vehicle's emissions. Malfunction Indicator Lamp (SERVICE ENGINE SOON ) This light on your instrument panel lets you know when your emission system needs service. The light will come on briefly when you start your engine to let you know thatthe system is working. If it does not come on when you start your engine, or if it comes on and stays on while you're driving, your system may need service. Your vehicle should still be driveable, but you should have your system serviced right away. 6-38