MVS Forums Moderator abscate made an interesting post about OBD-II readiness states during state smog emissions testing. It turns out that recently (2015 for California) some states have relaxed their rules about passing/failing cars without all monitors in the readiness state.
Yes, this is technical nerdery that can cause you (or used to cause you) immense headaches getting older Volvos to pass state emissions testing. If you’ve run across the term “drive cycle” before, you’re probably familiar with OBD readiness states without knowing it.
According to the EPA, these are the states performing OBD checks:
Currently Performing OBD Checks
- Alaska (Fairbanks and Anchorage areas)
- Arizona (Phoenix area)
- Colorado (Denver and Boulder areas)
- District of Columbia
- Georgia (Atlanta area)
- Kentucky (Louisville area)
- Nevada (Las Vegas and Reno areas)
- New Hampshire
- New Jersey
- New Mexico
- North Carolina
- Rhode Island
- Utah (Salt Lake, Davis, Utah, and Weber Counties)
- Tennessee (Davidson, Rutherford, Shelby, Sumner, Williamson, and Wilson Counties)
Will Require OBD Checks in the Future
- Missouri (St. Louis and Franklin County)
- New York
Unfortunately, none of these documents on epa.gov indicated which states have relaxed readiness states. I know California and Colorado have.
…Most other states follow the EPA rule of 2 for 1999 earlier, one for 2000 newer.
1999 earlier …one monitor not ready allowed
2000 later…only evap monitor not ready allowed
Thus actually helps with those annoying P0455 s!