Skip the auto shop - Our mechanics make house calls

Q: Car running rough and shaking

asked by on

My car is running rough and shaking. I went to NTB and from their code readings they stated I am having a misfire. They also found a problem related to the PCM. Additionally, they told me I have a fuel tank, or something of that nature open, and it is affecting my MPG.

Hello. I think the "fuel tank being open" you are referring to is a code for the evaporative emissions (EVAP) system. This system is used to capture fuel vapors and prevent them from entering into the atmosphere. If the powertrain control module (PCM) detects a problem with this system, it will illuminate the Check Engine Light. There are many different codes that correspond to the EVAP system. The cause of these codes can be anything from a loose gas cap to a pinhole in an EVAP line. The EVAP system can also be responsible for an engine misfire if the system purges at the incorrect time. However, your EVAP code and misfire code may or may not be related. This is because there are countless of other problems that could cause an engine misfire. I suggest you have a trained professional, such as one from YourMechanic, diagnose why your vehicle is shaking and replace any failing parts.

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: it has no power at all

Hi there: Some times when the battery has run it's course, it can't be recharged or even jump started. This typically occurs when it's starting to get colder outside; when cold cranking amps on the battery have worn out. It's...

Q: AC fan turns when tested to the battery but not turning when hooked up.

Hi there. The first thing that comes to mind based on your input is perhaps a ground wire is not properly attached to the AC control switch. However, it's also possible that the switch itself is faulty or there is...

Q: code po171 already changed spark plugs and ignition coils and was told by Firestone that was what it needed

Code P0171 is set due to a system lean reading. While worn or misfiring plugs or coils can cause the issue, they typically do not. Most common causes would be a mass air flow sensor or even a leaking intake...

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 Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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.