Code p0440, Check engine light comes and goes?

2010 DODGE RAM

175,000 MILES • 4.7L • V8 • 4WD • AUTOMATIC

KFERRA814

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My check engine light was on for a couple months reading code p0440, I figured it was clogged catalytic converter and assumed I was going to have to replace it soon. Then out of nowhere the truck started weird once and the light was gone, it has since come back on and went off again, but it will only go off the times it starts weird. what could this be? I’m totally lost.

Sep 5, 2024 at 6:22 PM

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The P0440 code refers to a general issue in the Evaporative Emission Control System (EVAP). So, there is a leak, I would check the gas cap first, but since it starts funny, I have seen the EVAP purge solenoid go out and stick open. Here is the location of the valve, remove it and try to blow air through it, if so, the valve is bad, you should not be able to have air pass through it without power to it. Check out the images (below). Let us know what you find.

Images (Click to enlarge)

Sep 6, 2024 at 6:24 PM