I’m not talking about plastic wrap, or even the Macarena. I’m sure that many of our clients would say that the world’s most annoying thing is Virginia’s emissions testing program. This is not the same as Virginia’s State Safety Inspection, which is a statewide program requiring an annual check-out of certain safety-related systems such as brakes, steering, lights, and things like that. The Emissions Inspection is only required if your car is garaged in Stafford, Prince William, Fairfax, Loudon, or Arlington counties, and certain cities in and around those jurisdictions. The Emissions Inspection is done every two years.
There are two main types of emissions inspections for passenger cars – OBD I and OBD II. Most cars and light trucks built after 1995 are OBD II certified. OBD stands for “On Board Diagnostics” and refers to the programming built into the car’s computer. OBD I cars have to have the tailpipe emissions directly analyzed by emissions testing equipment. OBD II cars are hooked to our emissions testing equipment electronically, instead of having the actual tailpipe emissions analyzed.
Regardless of whether a vehicle is OBD I or II, it has to pass some preliminary inspections before it can even be tested. Failure to pass any one of these preliminary steps prevents advancing to the next step.
The first thing the state requires an emissions inspector to do is what’s called a “preliminary safety check”. This includes checking for visible smoke, worn out tires, fluid leaks, the presence of a gas cap, and other things that might indicate mechanical problem. If the vehicle doesn’t pass this check, the inspector is required to fill out a “Rejection from Testing” form, which identifies the vehicle and the problem or problems that have to be fixed before continuing with the testing.
The next step in a Virginia emissions test is to verify that all of the emissions – related components originally installed on a vehicle are still there and hooked up. If not, they have to be replaced and hooked back up correctly.The final phase of the procedure for OBD I cars is to run them at 15 miles per hour, then at 25 miles per hour on a set of rollers while the emissions test machine monitors the exhaust gases. OBD II cars have their computer connected to the machine, which checks for the presence of any malfunctions that can cause excessive emissions. If you pass this part of the test, you’re done, and you can get the little stickers for your license plates from the DMV. If the car doesn’t pass this part of the test, you won’t be able to register or reregister it until it passes or you get a waiver. The waiver is given when you exceed a certain dollar threshold attempting to repair the emissions failure at a state-certified emissions repair facility. Keep in mind that not all emissions testing stations are certified emissions repair shops.
When an OBD II equipped vehicle has a powertrain code or codes stored in its computer, it will generally fail the emissions test. Check out the section on OBD II codes in this booklet for more info on them. We’ll always clear all the codes stored in the computer after we’ve fixed whatever was causing them; then the computer will check to make sure that everything is working the way it should. The computer uses what are called “monitors” to make sure each system is working properly, and these monitors must be “ready”. Some of the monitors can be reset to “ready” by just starting the car, assuming there are no malfunctions. The other systems will not reach a state of readiness until the car has been through a certain number of drive cycles during which specific parameters must be met – for example, reaching and maintaining a given speed, traveling a specific distance, reaching operating temperature, etcetera. Generally, if there is any condition that will set a code or pending code, the monitors will not advance to “ready”. Most model year 1996 through 2000 cars can have the emissions tested with up to two monitors “not ready”; 2001 and newer cars are generally only allowed one monitor “not ready”. If too many monitors are not ready, the car will be rejected from testing. Keep in mind that disconnecting the battery clears the computer too, so if your car needs an emissions test and a battery, either replace the battery after the test, or drive it for a few days to reset the monitors before bringing it in.