Q: Car failed emissions test

asked by on

My car failed an emissions test.

Your truck can fail an emissions test for a number of reasons. If I knew the results of the inspection I could give you some common causes of this failure. If the vehicle failed the visual check then there may be a part that is missing or not functioning as designed. If it failed the HC test then it may have a misfire or a failing catalytic converter. If it failed the NOX test then the EGR system may have a problem. A mechanic would need to know the results of the test in order to know where to start the diagnostic process.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Car failed emissions test

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: Heater not working

Your vehicle has a control valve in the heater hoses the either blocks or allows the hot coolant to flow into the heating system. This control valve is operated by engine vacuum via several solenoids that are controlled by the...

Q: with the#1 piston up were should the rotor button be pointing

The rotor button should be pointing to the number 1 position on the distributor cap when the number 1 piston is at top dead center (on the compression stroke). The pistons come up two times during the combustion cycle. Once...

Q: Where do I find the emissions control label?

The emissions control label gives you important information about the emissions system in the car, and what regulations it meets. This information may be necessary during emissions testing. You’ll find the label on the underside of the hood, on the...

Related articles

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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.