Gasoline, hybrid, light natural gas, and flex-fuel vehicles, model year 1976 or later
Diesel passenger cars and light trucks, model 1998 or later
Most other vehicles are exempt from smog inspections
Originally, smog checks included tailpipe, visual, and functional inspections. Today, most gasoline vehicles model year 2000 or newer and diesel vehicles model 1998 or newer no longer require a tailpipe inspection, where exhaust is analyzed while the vehicle is driven on a stationary dynamometer. That’s because modern cars are cleaner and have sophisticated onboard diagnostic systems that monitor and identify emission-control problems.
Rather than analyzing exhaust for excess emissions, technicians can connect directly to a modern car’s onboard diagnostics. If there is a problem with a vehicle’s emissions, a technician can read the assessment and quickly get an idea of what repairs might be required.
Smog check stations can provide guidance on the type of driving needed for a vehicle to complete its readiness monitors after a repair or memory wipe. In general, you'll want to follow these steps:
Fault codes can’t be hidden by erasing them or disconnecting the battery; the readiness monitors must be completed to determine if the fault still exists, or the vehicle won't pass a smog check.
If a vehicle’s readiness monitors continually won’t complete, it may mean that the vehicle has a malfunctioning component or sensor that needs to be adjusted or replaced.
AAA Club members receive guaranteed repairs and service from AAA Approved Auto Repair facilities. If your Check Engine light is on or your vehicle isn't passing smog checks for another reason, you can get peace of mind by having your vehicle worked on at a shop you can trust. Find an Approved Auto Repair facility near you.