* Get the Diagnostic Trouble Codes (DTCs) read: This is the most important step. The check engine light itself doesn't tell you *what* is wrong. A DTC is a code stored by the car's computer that indicates a specific problem. You can get this done in a few ways:
* Auto parts store: Most auto parts stores (like AutoZone, Advance Auto Parts, etc.) will read the codes for free.
* Mechanic: A mechanic will read the codes and can often diagnose the problem based on the codes and a visual inspection.
* OBD-II scanner: You can buy a relatively inexpensive OBD-II scanner for your own use. These plug into your car's diagnostic port (usually under the dashboard) and will display the codes.
* Once you have the DTC(s): Search online for the specific code(s). Many websites and forums will explain the likely cause of the problem. Remember to specify the year, make, and model of your car (2001 Pontiac Bonneville) when searching.
* Common issues in 2001 Pontiac Bonnevilles that trigger the check engine light:
* Oxygen sensor: These sensors monitor the exhaust and help the engine run efficiently. A faulty sensor is a common cause of a check engine light.
* Mass airflow sensor (MAF): This sensor measures the amount of air entering the engine. A bad MAF sensor can lead to poor performance and a check engine light.
* Catalytic converter: This component reduces harmful emissions. A failing catalytic converter can cause a check engine light.
* Ignition system problems: Issues with spark plugs, ignition coils, or the distributor can trigger the light.
* Evaporative emission system (EVAP) issues: Problems with fuel tank seals or other parts of the EVAP system can cause a check engine light.
Don't ignore the check engine light. Continuing to drive with a problem could cause further damage to your car. Getting the codes read is the first step to figuring out what's wrong and getting it fixed.
