2007 Mercury Mountaineer 4.0L with code P0455

Question

This code was detected and it said gas cap when I took it to get scanned. I finally found out that I needed the exact gas cap from the dealership not the regular standard from the auto part store. The dealership replaced the gas cap but the engine light was still on. They said I needed to get it cleared out completely. I took it to Advance Auto Parts and they say it cleared out. The next morning the engine light came back on but it says the gas cap but it's tighten on. How do I clear the code totally out or do I need to take it to the dealership to officially clear it out completely.

Answer 1

Hi there,

This code is basically telling you there is an evap leak. Sometimes it's the gas cap, other times it's the vent control valve. What you actually need to do is have is smoke tested and find the leak. Clearing the code is clearing the code. In other words, Autozone clearing the code isn't any different then the dealer doing it. You haven't fixed the problem yet which is why the light is coming back on.

Answer 2

P0455 MERCURY - Evaporative Emission Control System Leak Detected Gross Leak
Read more: https://www.autocodes.com/p0455_mercury.html

P0457 MERCURY - EVAP Control System Leak Detected Fuel Filler Cap Loose/Off
Read more: https://www.autocodes.com/p0457_mercury.html