Skip the auto shop - Our mechanics make house calls

Q: smog test incomplete.

asked by on

OBD catalyst/oxy snsr heat not completed. no engine check light on.

My car has 60000 miles.
My car has an automatic transmission.

A: If your Check Engine Light is not illuminat...

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car not getting enough fuel

P0300 is an engine code for multiple misfires. These are possible causes, vacuum leaks, damaged hoses or improper routing, fuel contamination, ignition system (ignition module, coil, spark plugs and wires,) or a fuel system issue. If there are specific codes...

Q: Overheating at the traffic light or while AC is on

You may have a restriction in your radiator or condenser that is preventing the cooling of the respective fluids that go through these parts. Restrictions will cause hot spots and therefore will not allow sufficient cooling of the refrigerant or...

Q: Took for smog test and fail said that it was supposed to be 430 but was 469. What do I do to fix it?

Generally, when the car fails a smog test, the smog shop will give you a print out and tell you what specifically caused the failure. Some common causes for failing these tests are faulty O2 sensors, bad catalytic converters, vacuum...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...