Skip the auto shop - Our mechanics make house calls

Q: OBD-II failed for smog check

asked by on

The OBD11 failed for smog check. What do I need to do?

A: Unfortunately without more information as t...

Unfortunately without more information as to why your Toyota Corolla did not pass the emissions test, it is difficult to determine the cause for the failed smog check. Provided that the ODB2 port itself has power and is allowing the emissions tester to read the computer, we would need to know what codes the computer populated in order to determine where to investigate necessary repairs. Typically, if you have active codes in the vehicle’s computer, then the Check Engine Light will also be illuminated. This is the first indication that a vehicle will not pass smog. If this is the case for your Corolla, I highly recommend that the next time your emissions test is due, observe the status of this light if it is on and enlist the help of a certified mechanic to help you troubleshoot the codes. Not only will they diagnose and repair the problem, they can aide in informing you if your Toyota is ready to be smog tested. This will help you avoid wasting time before smog checks.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Car is making a knocking noise. 2006 Toyota Corolla

Hi - your engine could be knocking from bad fuel, ignition problems or bad bearings. Check your engine oil level first - a low oil level could be the most damaging. If the Check Engine light is illuminated, have the...

Q: My transmission went out.

This sounds like a long and frustrating experience. I have a few initial thoughts about this. First, I'm wondering if this mechanic/shop has German car experience. Second, the car's older age may be contributing to the continuous problems. Thirdly, concerning...

Q: Can a bad muffler cause a smog test to fail?

Hello. You need to see why the last smog failure was for. If the failure was excessive O2 in the exhaust test, then it could be the muffler. If it is for high HC or CO then it may be...

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...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...