Diesel Smog Check in California
Diesel Smog Check - Since 2010 California has required all diesel trucks and diesel passenger cars which are 1998 model year or newer, and weight under 14,500 GVW, undergo a biennial smog inspection similar to their gasoline counterparts.
Any California certified smog check station is allowed to perform a diesel engine smog inspection. The diesel smog test will not include the emissions test portion of the regular inspection. There will be no tailpipe emissions inspection either. Diesel cars and trucks are not driven on a dynamometer during the smog test either.
The diesel smog test will focus on a visual inspection of your vehicle's emissions/smog components, a system check of the On Board Diagnostics (OBD II) system, a visual smoke check for excessive black (carbon) smoke, and an EVAP functional test. Diesel cars and trucks which fail the diesel smog test will have to get their vehicles repaired at a diesel vehicle repair shop before retesting.
Diesel smog inspections are required during a diesel vehicle's initial registration in California and once, every two years, thereafter. The diesel smog check cycle will continue for as long as the vehicle is registered in this State.
The Diesel smog test program applies to 1976 and newer passenger vehicles and trucks powered singly or in combination by:
- Natural gas
- Methanol / Ethanol fuels
Smog inspections are also required anytime a diesel vehicle is sold or bought in California. During a title transfer the Department of Motor Vehicles will not allow a vehicle to be registered unless it is presented with a valid smog certificate. There are special testing procedures for vehicles, which are classified as "Gross Polluters". These include Test Only and State Referee inspections.
Diesel Smog Test Exemption: The DMV does not require a California emission inspection (smog check) for the following types of vehicles:
- Any diesel car or diesel pickup truck which is 1997 model year or older.
- Any diesel truck which weights over 14,500 GVW.