Q: smog test incomplete.

If your Check Engine Light is not illuminated, there is not a fault with the system. Before a vehicle can pass emissions testing, certain readiness monitors must be completed. One of which is the heater O2 monitor. The vehicle will need a cold start full drive cycle completed to get that monitor to set.

Let the vehicle completely cool down overnight. The next morning start the vehicle and let it warm up and take it on a drive. Head towards the interstate. Merge into the interstate and get into the slow lane of traffic. Hold the throttle to where your speed is between 55-65 mph. Do this for 3 minutes. Then get off at the next exit and try to time your exit to where your vehicle can coast down to 30 mph without touching the brakes during exiting. USE CAUTION AND AVOID COLLISIONS. BRAKE IF YOU MUST. The point of this is to force readiness. Circle back around and get back in the interstate in the opposite direction and head back home. Once home, let the vehicle cool back down. A few hours should be plenty of time.

Start the vehicle, if the Check Engine Light is not illuminated, you should be ready for inspection. If the Check Engine Light is on, you will need a qualified technician, like one from YourMechanic, to determine what the fault is and which part will need replacement.