How Long Has Your Check Engine Light Been On?


Check Engine Light

Check Engine Light

Your catalytic converter could be the culprit.
One of the most common causes of a check engine light is a failed catalytic converter. The converter is the most important emissions device on your vehicle and some would argue the only true emissions component (I actually agree with them).  In order to understand why it’s important, you must first understand what the catalytic converter does.
The catalytic converter chemically changes the exhaust gas to reduce pollution.  All other components such as sensors, computer, etc… primarily function to control the gases that enter the converter so it can operate properly.  The biggest ‘converter killer’ is engine misfires. When the engine misfires, fuel is not properly burned.  Thus, pulses of rich fuel mixture can enter the catalytic converter and raise the temperature, causing reduced life or failure.  Engines in need of a simple tune-up will cause an engine to misfire and you may not even know it while driving.
On most newer models, the computer detects a problem and turns the ‘check engine‘ or ‘service engine soon’ light on.  Most people don’t know that there are 2 light modes:

  • Light mode #1:  light is on steady (no blinking)
  • Light mode #2:  light blinks while engine is running

If the light is flashing, that means that whatever the computer thinks is at fault could possibly damage the converter and it is not recommended to drive the vehicle while the light is in flash mode. If the check engine light is on steady, not blinking, and it seems to be running ok, then it should be safe to drive until you can get it checked out by a reputable mechanic.  It is not recommended to wait too long because the stress placed on a catalytic converter could mean the difference of being repaired to being replaced.
Make sure your shop has certified technicians who have been trained in computer diagnostics.  These technicians will save you valuable time and money when looking to pinpoint your engine problems.