In some states, your car will be required to be tested for tailpipe emissions to allow it to be driven on the road. The process is not terribly difficult but if the car fails, you will be required to make repairs to it then come back for a retest. The reason for testing is to reduce the impact on the air and environment and in heavily populated areas, it can help to reduce smog and increase air quality over time.
Preparing For Emissions Testing
There are a few things you can do to prepare for an emissions test but no one thing is going to magically get your car through the process. The best way to get through the test is to keep your car tuned up, change the spark, oil, and filters on the engine regularly. Keep the car well maintained through the year so that it is running properly at testing for the best possible chance of it [passing the test. The test is not an attempt to fail cars, in fact, some classic cars are waived so they are not subject to testing at all. The purpose is to keep the cars that are on the road running properly and reducing the ongoing impact on air quality.
When you arrive at the testing site, a technician will take your car to the shop and hook it up to the testing computer. They will -plug the testing computer into the car's OBD II port under the dash to scan for error or warning codes from the car's computer and put a sensor in the tailpipe. They will check for any lights on like the CEL (check engine light) or other warning likes that would indicate a problem with the engine and make a note of them. During this process, the tech will make a visual inspection of the engine and exhaust to look for missing or modified equipment that is not allowed on the car and make a note of that as well. The entire process can take about 30 minutes but might take a little longer on some cars.
Pass or Fail
Once the test has been concluded, the testing computer will print out the test results and the tech will bring the car out to you. The tech or a service advisor will go over the test results with you and let you know whether the car passed or not. If it did not pass, the reason for the failure will be explained to you so that you can get the car repaired and tested. In most cases, a failure will have a specific reason like a bad sensor or a defective part on the engine or another part of the car. It can be something as small as a PCV valve or as major as a bad catalytic converter. Whatever the reason for the failure, once the car is repaired it can be retested and if it passes, it will be issued the emissions sticker it needs to be legally driven on the road.
Contact a shop, like Teloloapan Muffler & Brakes II Inc, for more help.