How is the database used when passing the State Technical Inspection?

If you live in an area that requires annual emissions testing, you will need to take a two-part test. The test center will do two things: measure the gases in the exhaust with an exhaust pipe test, and…

If you live in an area that requires annual emissions testing, you will need to take a two-part test. The test center will do two things: measure the amount of gases in the exhaust gases with an exhaust pipe test and check your OBD (on-board diagnostics) system. What role does the OBD system play here? Why do I need an OBD system check if the site is doing an exhaust pipe check?

Two Reasons for a Two-Step Test

There is actually a very simple reason why a test center in your area would need an OBD check in addition to an exhaust pipe check. Contrary to popular belief, the OBD system does not measure gases other than oxygen. An exhaust pipe test is necessary to analyze the various gases produced and to ensure that your vehicle is within government limits.

The second reason is related to the first. The exhaust pipe test only checks for the presence of gases in your emissions. It cannot assess the condition of your emission control components. That's what the OBD system does - it monitors your emissions equipment like the catalytic converter, oxygen sensor, and EGR valve. When there is a problem with one of these components, the car's computer sets the time code. If the problem is detected more than once, the computer turns on the Check Engine light.

What does the OBD system do

The OBD system does more than just light up when a part fails. It is capable of detecting the progressive wear of your vehicle's emission control system components. This helps to avoid potentially serious damage to the vehicle and also ensures that you can replace failed emissions control equipment before the vehicle starts to seriously pollute the environment.

If the Check Engine light is on on the dashboard, your vehicle will fail the emissions test as there is a problem that needs to be fixed first. However, your vehicle may not pass the test even if the "Check Engine" light is off, especially if you failed the gas cap pressure test.