Your vehicle will automatically fail the smog check if the check engine light is on so before you bring the car to the smog check station, you must first fix the problem that is making the light turn on in the first place. We’re going to describe steps to turn off your check engine light on the cheap.
First, you need to figure out what is causing the check engine light to be turned on. To do so, you will need a device called an On Board Diagnostics (ODB-II) code reader and plug it into your car. The device will display the error code(s). Since ODB-II code readers can can anywhere between $100 to $300, you should go to your nearest auto parts store such as O’Reily’s (Kragen), Autozone, or Pep Boys because they will let you borrow a code reader as long as you leave some collateral such as an ID at the front desk.
Connect the ODB-II reader to your car’s serial port interface usually located under the dashboard on the driver’s side of the car. Press the “Link” button on the reader and it will display a listing of error codes. Write these error codes down. You can ask the friendly person at the auto parts store about the error codes and even the parts that need to be replaced. You should also research about the error codes online at odb-codes.com.
Many check engine light problems stem from a faulty oxygen sensor in the exhaust system. Error code P0136, for example, indicates that the oxygen sensor at Bank 1 Sensor 2 is faulty. Bank 1 refers to the side of the engine that has the #1 cylinder which is typically but not always the passenger side. Sensor 2 indicates the second sensor from the front of the car.
If you’re handy, DIYer, and able to replace the parts yourself, you can potential save yourself at least $200 in parts and labor at the repair shop. If can’t do it yourself, at least, you can go to the repair knowing what’s wrong with your car and save yourself from any run around.
Once you have replaced the broken parts, you can drive your car for approximately 60 miles and it will automatically clear the error codes. The check engine light will turn off. If repaired at a shop, the shop can clear the error codes with ODB-II code reader.
With the check engine light off, your car is ready for the smog check.
Note: Even though you can turn the check engine light off temporary with the code reader, that doesn’t solve the problem with your car’s emissions and you will most likely fail the smog check. Save yourself some time and money by fixing the problem first.
