At times, this code can be set by not tightening your gas cap completely. If this is the case, and your light has not been reset, this can slef reset after a few key cycles. If the code returns you can start with simply replacing the gas cap, sometimes the cap can loose its seal setting this code. If you are still experiencing issues I then would recommend having a "smoke test" performed if you have a leak significant enough to be detected you will find it with a smoke test performed by a mechanic.
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A. J. Valle
A Smoke Test would be best to find the source of the EVAP Leak. EVAP Systems are VERY sensitive to the Pressure Values measured by the various Sensors and Solenoids, and something as small as a pinhole leak can trigger the Check Engine Light. A Smoke Test will usually show where the leak, no matter how big or small, is coming from.
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Curry's Auto Service
〉 Answered on Jan 17th, 2012 by Judy Curry, Co-Founder and Vice President of Marketing at Currys Auto Service
Joyce, you're not alone! An evap leak is the second most common cause for "check engine" light problems on cars today, according to the CarMD Vehicle Health Index. A "small evap leak" is often accompanied by a PO442 diagnostic trouble code. Many times the cause is simply a loose or cracked gas cap. A quick way to confirm this is to fill up your tank, tighten the gas cap and see if the light turns off. However, other sources for the leak can be a hose or a cracked fuel line, so don't ignore the problem or just assume it's the gas cap. Best of luck! Kristin Brocoff, CarMD.com Corp.
〉 Answered on Jan 17th, 2012 by Kristin Brocoff, Director of Corporate Communications at CarMD.com