What Causes the Engine Malfunction Indicator Light in a Sedan?
1 Answers
Almost all engine-related malfunctions can trigger the illumination of the warning light. Diagnosis must be based on the fault codes read by the diagnostic tool for further judgment. Common causes include: 1. Dirty throttle body and fuel injectors. 2. Excessive engine carbon buildup. 3. Leaks in the intake system, crankcase ventilation system, or secondary air system. 4. Clogged three-way catalytic converter or damaged oxygen sensor. 5. Use of substandard fuel. 6. Incorrect valve timing. 7. Stuck open exhaust gas recirculation (EGR) valve. 8. Using summer-grade lubricants in winter or overfilling engine oil.