Do you need a smog check for a registration renewal, change of automobile ownership or out-of-state vehicle? Welcome to HJ Smog, your professional and reliable smog inspection service in Concord, CA and the surrounding areas. Our smog station is able to perform smog tests for cars, hybrids, trucks, SUVs, RVs, and fleet vehicles. We complete your smog check in a swift 10 minutes and you can come in with no appointment necessary. If your car does not pass the first time, you are eligible for a free retest.