1997 Pontiac Grand Prix Owner's Manual - Page 146

If the Light Is On Steady You may be able tocorrect the emission system malfunction by considering thefollowing: Did you recently put fuel into your vehicle? If so, reinstall the fuelcap, making sure to fully install the cap. The diagnosticsystem can determine if the fuel cap has been left off or improperly installed. A loose or missing fuel cap willallow fuel toevaporate into the atmosphere. A few driving trips with the cap properly installed should turn the light off. Did you just drive through a deep puddle of water? If so, your electrical system may be wet. The condition will usually be corrected when the electrical system dries out. A few driving trips should turn the lightoff. Are you low on fuel? As your engine starts to run out of fuel, your engine may not run as efficiently as designed since small amounts of air are sucked into the fuel linecausing a misfire. The system can detect this. Adding fuel should correct this condition. Make sure to install the fuel cap properly. It will take a few driving trips toturn the light off. Have you recently changed brands of fuel? If so, be sureto fuel your vehicle with quality fuel (see "Fuel" in the Index). Poor fuel quality will cause your engine not to run as efficiently as designed. You may notice this as stalling after start-up, stalling when you put the vehicle intogear, misfiring, hesitation on acceleration or stumbling on acceleration. (These conditions may go away once the engineis warmed up.) This will be detected by the system and cause thelight to turn on. If you experience one ormore of these conditions, change the fuel brand you use. It will require at least one full tank of the proper fuel toturn the lightoff. If none of the above steps have made the light off, turn have your dealer or qualified service centercheck the vehicle. Your dealer has the proper test equipment and diagnostic tools to fixany mechanical or electrical problems that may have developed. 2-72