Evap code won't leave me Alone!!!

[Layne]

Hey guys, Mandy's car got a Evap code recently. I cleared it, and thought the gas cap was loose, so it was tightened. That was yesterday. Well, it came up again today. It's an 02 Malibu 3.1 with 50,000 miles. These evap codes get me. I forget the number, it's something like P044.....

[Irish_Alley]

Some of the causes for p0440 are the gas cap is not installed or working properly,the purge solenoid has failed or the canister is plugged and not working properly. Some things to do remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back. inspect the EVAP system for cuts/holes in tubes/hoses Inspect for damaged or disconnected hoses around the Evap purge solenoid, check and/or replace the sensor, check and/or replace the purge valve or have a professional use a smoke machine to detect leaks

[Layne]

Did the whole gas cap deal. Would this cause a driveability concern, because she says nothing is out of the ordinary?

[Irish_Alley]

no signs or concerns but it wont pass inspection in most states its only pretty much a pollution control device want to say your mpgs might drop a little. its not like a ball joint when it fails your care will go screaming out of control but i would fix it when you can

[VileZambonie]

Can't help you without the exact DTC

[Josh454]

P0440 is a large leak, P0442 is a small leak, P0446 is purging when it shouldn't.  More than likely it's leaking somewhere...could be sticking vent solenoid or cap.  Could also be the tank, filler neck, canister, lines etc.  Make sure that when you're filling up that you're not doing it with the engine running and that you're tightening the cap fully.

[Blazin]

I have had to replace several purge solenoids in the last year or so on GM products. I would have it smoked before spending the money on on though. New gas cap might fix it? If not they are not huge money.

[Layne]

446 sounds about right. Shes out of town now. I just cleared it the second time last night. It had two, but they were both the same...

[frogman68]

My Cavalier has been showing the code for the last year I swapped the purge solenoid when I broke it swapping the clutch it is still there, mine has a air valve (like a tire ) thinking now I know what it means might put some air (like 5 psi) and check it in a hour. I have not noticed any issues except the light is on lol

[VileZambonie]

If you tell me what the exact codes are I can guide you through some do it yourself tests without a smoke machine but do not attempt to pressurize the system with air. That's a recipe for disaster.

[frogman68]

If you tell me what the exact codes are I can guide you through some do it yourself tests without a smoke machine but do not attempt to pressurize the system with air. That's a recipe for disaster.

Wifey let me work on the Blazer tonight guess it was a good think since I didnt put air in the purge solenoid. I have only the cheapo scan tool P0446 something in the Haynes book says massive leak in the evap system, might change my gas cap..

[jaredts]

I had the slow evap leak on an s-10 blazer and it required a new fuel pump.  Something about an oring on the harness (it was fixed under warranty).

[Layne]

She's driven all over this weekend and no problems so far. I put some wd 40 on the gas cap gasket. She wants to buy a new one that locks anyway. Hopefully it was that easy.

[Layne]

K it's back again. 2 P0446's and her dad has a 06 monte with 2 P0445's. I have no ideas where any evap stuff is lol. I think with the monte it's just a overfull gas tank deal. I just cleared it.

[VileZambonie]

It's not an overfull gas tank. the evap system monitor won't run until it reads below 3/4.

The most common cause for that code on that car is a faulty Canister Vent Solenoid

1. Perform the purge/seal test using the scan tool if you have access. The fuel tank pressure sensor value should start at 1.3v-1.7v and increase voltage with vacuum.

2. Monitor the fuel tank pressure sensor to be stable when the purge solenoid is turned off (seal).

3. If the vacuum still increases, disconnect the electrical connector from the purge solenoid under the hood.

4. If the vacuum still increases, remove the vacuum hose and check for vacuum leaving the solenoid when it is still electrically disconnected. This solenoid is Normally Closed (NC) and should not allow vacuum to pass when disconnected. If vacuum is present, replace the purge solenoid.

5. If the vacuum stabilizes during the seal, turn the vent solenoid off and check for the vacuum to drop quickly.

6. If the vacuum does not drop, remove the electrical connector from the vent solenoid. The vent solenoid is Normally Open (NO) and should vent when disconnected.

7. If the vacuum does not drop, remove the hose from the vent solenoid and retest.

8. If the vacuum drops, replace the vent solenoid.

9. If the vacuum does not drop, disconnect the canister.