You are now in California, or in any other state that requires you to have a smog certificate every one to two years in order for your registration renewal. Your car is not eligible to pass the smog test. However, the “check engine lamp” on the dashboard lights up. What now? This could lead to costly repairs if you don’t have a trustworthy family member who can clear the light for your car so it is ready to pass the smog test. First, determine which code or combination of codes are stored in your car’s computer. Either borrow or purchase an On Board Diagnostics (odbii) code reader. Plug it into the serial port interface of your car and then download the error codes. You might consider going to an auto parts shop to borrow their code reader, as they can charge between $99 to $400. Pepboys and Autozone both allow you to borrow one, provided you provide collateral. After plugging in the code reader, hit the “link” button and the code reader will return with a list of error codes stored on your car’s computer. These codes should be written down for later reference or to help you find the correct part at the store. […] read more