I have a check engine light with code P0456 (Evaporative Emissions System - Small leak detected).

I replaced the gas cap and cleared the code, but the CEL came back after couple of days. Next step is to take it to a mechanic and have them hook up a smoke machine to find the leak, but this is going to cost me. My next emission test in in about a year. Can I keep driving the car for while(1 year) as I have not noticed any decrease in performance or fuel economy?

Will this make the "leak" worse or damage any other components?

Car: 2006 Mitsubishi Lancer ES 2.0L Automatic 225,000Kms

1 Answer 1


The code P0456 indicate a leak that is not so severe, compared to a P0455. Since you already replaced the fuel cap, so the problem can be in many other parts of the fuel system that can be very painful to diagnose. It should be ok to drive like that, but keep an eye to see if the code is not "promoted" to P0455 or if the leak is noticeable (visually or by smell).

  • Thanks for the advice. I have a scan tool (ScanGauge II))attached to the car all the time so I can check what code it is frequently. I don't see any visible leaks under the car and there is no gasoline smell.
    – rana
    Aug 24, 2016 at 14:08

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