Q: P0442

asked by on

We have code P0442 keep coming up we changed the gas cap but the still keeps saying tighten gas cap could we have a small leak in the evap system or should we try to replace the gas cap again?

My car has 120000 miles.
My car has an automatic transmission.

As you may already know, this may be related to a faulty or leaking gas cap, however this can also be related to several other factors such as the following:

  • A non-conforming gas cap (i.e. not factory/original brand)
  • A small leak/hole in a fuel vapor hose/tube
  • Other small leak in EVAP system
  • Faulty vent o-ring seal
  • Defective vent valve
  • Defective purge valve
  • Defective leak detection pump

To avoid any unnecessary repairs, I would suggest having a professional from YourMechanic come to your home to take a closer look at your vehicle’s evaporative emissions system and further diagnose your trouble code.

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!

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: Battery light was on and now car won't start and keys stuck in ignition

Hi there. It more than likely that you are experiencing an issue with the alternator or the main relay as opposed to the battery itself. Once your car starts, power to all components and accessories is provided by the alternator;...

Q: Replaced the transmission with a 04 tranny and it shifts funny when I I'm coming to a stop. It's like a straight shift sometimes

Hi there. The problem is the generation of the transmission is different, meaning the wiring harness inside the transmission is different. However, the range selector will not cause the transmission to not shift to the lower gears. The newer version...

Q: Unresolved leakage problems

Have the oil pressure tested to see if it is low, or the oil sensor is reading wrong. Also have the engine compression tested to see if the cylinder number 2 has a problem or not. The P0302 code...

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...
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.