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p0496 problem

03-03-2011, 01:09 PM
My 04 cavalier (2.2 ecotec) has a code p0496. I know this is something to do with the evap canister and some kind of valve, but what exactly is going on here, and what does this purge system do? Any suggestions on how I should approach the elimination of this issue are greatly appreciated.

03-03-2011, 01:13 PM
I must note that i cleared the computer about a week and a half ago and the cel didn't come on until about three day ago. I cleared it again and it hasn't come on again yet, but I suspect that it will. I have noticed that it turns on when i first start the car and is idling for a couple of seconds before i set off for my destination.

03-03-2011, 07:01 PM
Check the fuse/relay for both the Purge and vent solenoids for the EVAP system.

The Vent control solenoid is the most probable cause, being exposed to more elements.

03-08-2011, 05:56 PM
ok thank you. I just went out and tried to find the fuse/relay and I didn't see them at all i checked under the hood and behind the panel on the drivers side is there another location of fuses and relays?

03-08-2011, 06:17 PM
also i can't find the location of the canister itself. in my last two cars it was in the engine bay

HiFlow5 0
03-08-2011, 06:22 PM
When you clear the code, the PCM needs to go through drive cycles to test all its monitoring points before it determines normal engine operation or a fault. If the monitors pass, then no code, if a monitor fails, then a code is flagged as a pending code. The second time that monitor is failed a MIL is generated to notify you of something wrong.

Try these pin point test procedures and see if you can find a solution to your issue. If you could right click and "save as", I'm going to be pulling the link down in a few days to save bandwidth on my server.


03-08-2011, 06:24 PM
ill bet its by the gas tank or something... what a pain

HiFlow5 0
03-08-2011, 06:27 PM
ill bet its by the gas tank or something... what a pain
I'm not finding the exact location in the shop manual, but its either in the engine compartment bolted to the frame or near the gas tank. It's used to vent vapor from the gas tank and recycle back into the engine, so you might be able to follow the vent tube from the gas tank to its location.

03-08-2011, 06:36 PM
ok i'll put it up on jacks and see what i can say:)

03-08-2011, 07:08 PM
pretty sure the evap can is in the passenger side fender. there is a hard plastic line running from the intake to it.

03-08-2011, 07:49 PM
ok so i have it up now and i found a square box between the trunk well, and the gas tank that i believe is the canister. i followed the larger hose and i found this box (it is the one with the sloped bottom)
is this the part that is having the problems?

hmmm i'm doing a bit of research here and i found this part on the autozone website
http://i.ebayimg.com/05/!CB3doQwB2k~$(KGrHqQOKnMEz4BNvjL9BNJPoocHHQ~~_1.JP G?set_id=8800005007
i'll take quick look and see if i can find this one as well


HiFlow5 0
03-08-2011, 08:10 PM
That's eBay link is the canister purge solenoid, which controls where the vapor is sent, either to the motor or though the canister.

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03-08-2011, 08:13 PM
ok so update... i took the vent solenoid out and took it apart. and found that it is completely filled with spider eggs so i cleaned them out and i will see what happens when i reinstall the old one

03-13-2011, 05:54 PM
check engine light came back on today... I have the car in the shop for oil change so i'll tinker around a bit. how many ohms should the vent solenoid, and the purge solenoid be at?

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