Your option at this point is to get a second opinion either from another smog station or the state's Smog Check Referee's Office. You may contact the Bureau of Automotive Repairs Investigations Unit as well however they will recommend you first visit the state smog check referee, and if it is found that the smog station which failed your Chevy Truck made a mistake they will initiate an investigation, and you might be able to recover your smog inspection fee from the smog station. Note this process may become lengthy. If you'd like to schedule an appointment with the state's Referee's Office call (800) 622-7733. They will recommend you a local referee field station.