★ ENGINE TECH · ALL 1996+ VEHICLES

OBD-II Readiness Monitors Explained

QUICK ANSWER

Readiness monitors are self-tests your vehicle runs automatically while driving. Categories: Catalyst, EVAP, O2 Sensor, EGR, Heated O2, AC, Secondary Air, A/C. California requires all monitors (with 1-2 incomplete allowance) to be 'COMPLETE' to pass smog inspection.

Common OBD-II Readiness Monitors smog issues

Monitors reset after battery disconnect or code clear, requires 50-100 miles to recomplete

How to fix

Drive 50-100 miles of mixed highway + city, full warm-up cycles

Typical repair cost

Free — just drive time

Common questions

What is OBD-II Readiness Monitors?

Readiness monitors are self-tests your vehicle runs automatically while driving. Categories: Catalyst, EVAP, O2 Sensor, EGR, Heated O2, AC, Secondary Air, A/C. California requires all monitors (with 1-2 incomplete allowance) to be 'COMPLETE' to pass smog inspection.

What causes a OBD-II Readiness Monitors smog failure?

Monitors reset after battery disconnect or code clear, requires 50-100 miles to recomplete

How is OBD-II Readiness Monitors fixed?

Drive 50-100 miles of mixed highway + city, full warm-up cycles

What does fixing cost?

Free — just drive time