Q: Car runs rough below 40 MPH

asked by on

My car runs rough when driving below 40 MPH. The emission and low tire pressure lights are on, and I am getting OBD codes P0171, P0301, and P0316.

The code P0171 means that the engine running lean, which typically stems from a few possible sources: a faulty mass air flow sensor, or clogged intake manifold gaskets or fuel filter. The codes P0301 and P0316 can mean that cylinder number one is misfiring, which could stem from the coil. I recommend that you have a mechanic, such as one from YourMechanic, come to you and run a full diagnostic on your engine misfire issue, then estimate the repairs needed to fix your Windstar.

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
  1. Home
  2. Questions
  3. Car runs rough below 40 MPH

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: ABS Light, car shakes while braking

Usually when the ABS light is on the dashboard it's caused by a faulty wheel speed sensor, ABS module, or low brake fluid levels. The fact that the car shakes when you apply the brakes at 60 mph is concerning...

Q: Error code P0171 and P0374

Hi and thanks for contacting YourMechanic. If the vehicle went into limp mode, then the computer is making this happen to prevent the engine from any damage. Check the camshaft sensor for proper timing to the camshaft. Look at the...

Q: How do I replace the airflow sensor on my 1985 olds 98

You definitely want to reset the computer when you make a repair like this. Resetting the computer will allow it to check the new component for proper operation and set a Diagnostic Trouble Code if there is still a problem....

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.