California smog check regulations allow for one (1) incomplete or not ready monitor, on all 2001 and new model year vehicles. All emission monitors, accept one (1) must be "complete' or "ready" in order to pass the smog check if your vehicle is 2001 model year or newer.
2000 model year and older vehicles are allowed two (2) monitors.
The State of California is considering requiring all monitors be "ready" or "complete" in the near future.
