Q: Engine misfired during smog check

asked by on February 05, 2016

My engine misfired when doing the smog check.

If your engine has a misfire then that can occur for a number of reasons. If it suddenly occurred during a smog test then something may have been knocked loose during the inspection. It is not uncommon to have a vacuum hose come loose and cause this. If it is not a hose then it may have a bad ignition coil or spark plug. The computer would need to be scanned for codes to see which cylinder is misfiring. A mechanic would use the codes to determine if one of these parts is bad and to possibly check the compression of the engine. I recommend that you have your engine misfiring issue diagnosed and repaired as soon as possible to prevent further damage.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

What does the Engine Oil Hot, Idle Engine message mean?

The Engine Oil Hot, Idle Engine message can appear on your driver information center (DIC). When the DIC displays this alert, it means that the temperature of the engine oil is too hot, and the car should not be driven....

P0300 and P0305. Pending: P0304, P0306, P0171, P0174, P2196, P2198

Hi there. The issue that maybe happening is the are fuel injectors that are not firing and there is a vacuum leak on the engine. Possible multiple sensors are not working causing the P2196 and P2198 codes to appear. For...

Spark Plugs spark once

Either a failing crankshaft sensor or impulse wheel could be the cause of the fluctuating RPM reading. The crankshaft sensor signal is often used to start both fuel pump operation and start the ignition coils with the camshaft sensor setting...

Related articles

How to Get Smog Technician Certified in Virginia
Automotive technician jobs include smog certified emissions inspectors. In Virginia, you need to work at a certified repair facility.
What Does It Mean When My Car Is "Burning" Oil?
Burning oil is usually caused by leaking oil that burns up on hot engine or exhaust components. Fix leaking oil to prevent expensive car repairs.
What Is the Purpose of Engine Gaskets?
Engine gaskets work as seals to maintain pressure, hold fluids, and prevent debris from entering the engine. Gaskets are vital for engine performance.