P0442

[don]

Hi, I have a 97 chevy malibu 3.1 and am getting a P0442 small evap leak, but only with like 1/4 tank of gas, fill up and reset my computer and everything is good until I get low fuel and then it starts coming on, any help is appreciated, Thank You

Topic

[Billy]

Smoke test

[don]

Can’t afford that right now, that’s why I’m here

[Billy]

[don]

PERFECT!!!! THANK YOU!!! I have seen the top and bottom videos but my system cant take more than 1 psi so the bike pump will work perfectly. Thanks again.

[Doug Beard]

Also worth your time to check the purge and vent solenoids. Briansmobile has a good video on that.

All you need to test them is a set of jumper wires. Pull them off the vehicle carefully and connect them to 12 volts DC (your car battery)

The purge solenoid is CLOSED when not energized. You should not be able to blow through it that way. Also try sucking a vacuum on it with your mouth. It shouldn’t leak down at all. When energized, it should give a little kick and open up. You should then be able to blow through it.

Your vent solenoid is OPEN when not energized, and CLOSED when energized. The process for checking it is the same.

These are the only two moving parts in this system. They have a tendency to not seal perfectly as they get old.

hope that helps.

[don]

Didnt get to use the smoke method I just changed the gas cap (which I already did less than 7 years ago just because the strap was broke and didnt want to lose it, it had 120,000 miles on it compared to 40k on this newer OEM one) which is pretty much why I ruled it out, who knows, ran the service bay test with my tech 2 and passed right away. thanks for all the help.

[Mike]

Thanks for posting the solution.
Nice that it was a rather inexpensive repair.

For anyone wondering why the code only appeared between 1/4 and 3/4 of a tank of gas, it’s because the EVAP system doesn’t test for leaks when fuel levels are above 3/4 or less than 1/4.

[Author]

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