Understanding readiness

Your car’s self-checks, explained.

Saw “not ready” on your report? Start with the exact monitor name and your vehicle details. Use the search above to look for manufacturer drive-cycle information.

What is my car checking?

Readiness monitors are emissions self-checks run by the vehicle’s onboard computer.

READY / COMPLETE: the self-check has run. This alone does not guarantee a passing inspection.
NOT READY / INCOMPLETE: the self-check has not finished. It does not identify a bad part by itself.
NOT SUPPORTED: the vehicle does not report that check as supported.

Readiness, diagnostic codes and the check-engine light are separate information.

Which monitors need help?

Copy the exact label from your report or scanner: catalyst (CAT), oxygen sensor (O2), oxygen-sensor heater (O2 HTR), evaporative system (EVAP), EGR/VVT or the specific diesel monitor. Not every vehicle supports every monitor.

Why more miles may not be the answer.

A battery disconnect, code clearing or repair can leave checks unfinished. Some monitors need particular temperatures, speeds, loads or time with the engine off. No single mileage works for every car.

Start with reliable sources.

The search opens Google with your vehicle details and selected monitors. Look for manufacturer manuals, official service information and manufacturer bulletins hosted by NHTSA. BAR explains California testing requirements; those requirements are different from a manufacturer’s drive pattern.

Match the year, make, model, engine and exact monitor before relying on a result. Search results are not automatically verified instructions. Some vehicles have no freely available matching procedure.

Use any procedure carefully.

Read it while parked. Follow traffic laws and use only safe conditions. Ask a qualified repair provider for help with unfamiliar procedures or a monitor that stays incomplete. Do not clear codes simply to turn off the light before inspection.

Recheck monitor status afterward. Completing a drive pattern does not prove the monitor finished. Sacramento Smog Dog provides test-only inspections.

BAR OBD Test Reference · Official Smog Check guidance · ASK THE DOG