Know if the Check Engine Light Is an Emission Problem


  1. Most auto parts stores like Auotozone, O'reily, Pep Boys, etc, will let you use their scan tool in their parking lot. Most will show you where to hook it up and how to read it.
  2. Depending on the make model and year of your car, the "OBD" (on board diagnostic) will plug in under the hood, usually near the fire wall, or under the dash, usually on the driver's side by the driver's right knee.
  3. After the OBD has run its diagnostics, it will display codes that corespond to what is making your check engine light come on.


  • There are some inexpensive obd testers that use a bluetooth conection to your cell phone or laptop with a coresponding program install. Check Ebay, I think one is call ELM but I'm not sure


  • Be sure to have parts profesionally installed if you aren't confident in your mechanical abilities.