1998 Cadillac DeVille Owner's Manual - Page 146

If the Light Is On Steady You may be able to correctthe emission system malfunction by considering the following: Did you recently put into your vehicle? fuel If so, reinstall the fuel cap, making sure to fully install the cap. The diagnostic system can determine the fuel if A cap has been left off or improperly installed. loose or missing fuel cap will allow to evaporate into fuel the atmosphere. A few driving trips with the cap properly installed should turn light off. the Did youjust drive through a deep puddle of water? Have you recentIy changed brands fuel? of If so, be sure to fuel your vehicle with quality fuel (see "Fuel" in the Index). Poor fuel quality will cause your engine not to runas efficiently as designed. You may notice this as stalling after start-up, stalling when you put the vehicle into gear, misfiring, hesitation on acceleration or stumbling on acceleration. (These conditions may go away once the engine is warmed up.) This will be detected by the system and cause the light to turn on. If you experience oneor more of these conditions, It least one change the fuel brand you use. will require at full tank of the properfuel to turn the light off. If none of the above steps have made the turn off, light have your dealer or qualified service center check the vehicle. Your dealer hasthe proper test equipment and diagnostic tools to any mechanical or electrical fix problems that may have developed. If so, your electrical system may be wet. condition The will usually be corrected when electrical system the dries out. A few driving trips should turn light off. the Are you low on fuel? As your engine starts to run out fuel, your engine may of not run as efficientlyas designed since small amounts of air are sucked into the fuel line causing a misfire. The system can detect this. Adding should correct this fuel condition. Make sure to install fuel cap properly.It the will take a few driving trips to turnlight off. the 2-75