Skip the auto shop - Our mechanics make house calls

Q: EVAP Small Leak Code P0442 Lit MIL. Code cleared, has not reappeared. But, Diagnostic tool still shows Emission Related DTC's

asked by on

The other day, my Check Engine light came on. I used my Diagnostic Tool to check it, and code P0442- EVAP System (Small Leak). I cleared the code, and it has not come back on since (I've probably driven the car 15 times so far). I have a couple small question related to this: 1) could it have been caused by a loose oil filler tube? I was cleaning under the hood and noticed it was loose so I opened the oil cap, jiggled the tube around, then JB-welded it back into firm place. I checked my gas cap and it was closed properly, but I re-sealed it just to be sure. 2) More importantly, every time I have used my diagnostic tool to check the car since, it shows a yellow light and says "Emission Related DTC's" but says no Powertrain DTC's or freeze frame data are present. A few of the monitors are flashing red (EVAP, O2, etc.) and I read that it could be because they havent yet completed their tests. When will it go back to green? All codes were cleared. Does it take a while?

My car has 90000 miles.
My car has an automatic transmission.

In order for all the monitors to clear you will have to do a lot of driving to see if it clears. The last two to clear take highway driving at a steady speed to clear and may take a couple times to clear or set a code if it cannot pass them after the testing has been done. The oil dipstick tube being loose will not cause the code you had. Keep driving the vehicle normal and it should pass all the monitors soon. I recommend having a qualified technician, such as one from YourMechanic, inspect the codes related to your Check Engine Light and diagnose the relevant systems more thoroughly in person.

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!
  1. Home
  2. Questions
  3. EVAP Small Leak Code P0442 Lit MIL. Code cleared, has not reappeared. But, Diagnostic tool still shows Emission Related DTC's

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: Advice on buying an O3 Hummer H3

Yes they do. I have a lot of customers that have had them go bad, and usually it was before 100,000 miles. Don't buy the Hummer. They have all kinds of problems. That's one of the reasons they stopped making...

Q: Died,then wouldn't crank for a few min then cranked and drive but cut out once in the way back home.

This may sound like a dumb question, but when was the last time you put gas in it? It may be possible that the fuel gauge sending unit is failing and giving you a false reading. It is also possible...

Q: code P1780

The code is for a possible problem with the transmission control switch on the shifter. The switch should be cycled during the scan test or it will set the code. If the code is still set then you will need...

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.