I know there are 100s of threads on this trouble code, which I have been reading though for the past couple days. To make a long story short, I am getting a trouble code p0441 on my 96 camaro m6. The car runs and drives great, no gas smell coming from rear... Evap Emission Control Purge flow Fault means the the solenoid is either stuck open or bad. I have replaced this part before with one from autozone(probably garbage). Now my question is: Is it true that if I pull the pigtail off of the actual evap solenoid, then take off the lower vaccum line(one that goes to the vaccumm switch, then to the evap canister, then there should be no vaccumm, as the solenoid should be CLOSED by default? Which In my case, I get vaccum if the solenoid is plugged in, or unplugged, constant vaccum at idle sitting in my garage. Now I have showboxes diagrams, and have made sure everything is hooked up the way its supposed to. Blew compressed air through the lines, no cracked or dry rotted lines or hoses. I even took a multimeter and tested the pigtail wires, they show 12-13 amps while the car is running, so the solenoid has power. I had read somehwere that it should only be replaced with a GM brand solenoid from the dealer, as the aftermarket ones can cause problems. I just want to know if theres another way to test, before I shell out the $75.00 to the dealership for a part I already changed. Another question I have, is how do you know if a Evap Canister is bad? I took mine out, it doesn't smell like gas, no cracks, If I turn the canister upside down and shake it, chucks of charcaol come out of all three hose connections at the top, But Im assuimng that would be normal, becuase I am shaking it upside down. In advance I apologize for creating yet another thread on this topic, But I actually haven't found a direct answer to properly test the evap solenoid itself. I was also told that the canister wouldn't have anything to do with purging, that is all controlled by the EVAP purge solenoid, not the vaccum detection switch or even a bad canister (unless you suck in charcoal) There is another part about 2 feet from the gas tank line going to the canister, but this had no power to it, looks more like a filter or a trap to not allow gas fumes out.

Thanks for the help.

 

You can test the EVAP solenoid by putting the car in "field service mode" and seeing if the solenoid passes vacuum. When not in field service mode, no vacuum should pass. Attach a vacuum tester to the top port (normal vacuum from throttle body) on the EVAP solenoid and pump it up to about 20" hg. It should hold. When you initiate FSM, the vacuum should immediately fall off (solenoid opens). You could test the integrity of the solenoid by capping the hose from the bottom port (hose to vacuum switch and charcoal canister) and see if it holds vacuum when in FSM.

Initiate field service mode by turning key ON, but engine not running. Connect pins 5 and 6 on the DLC with a jumper wire. FSM will activate the EVAP and EGR solenoids. High speed fans will come on.

 

Thanks shoebox, sorry I misspelled your name.. Well, If you could answer one more question for me, that would be great. Went to test the purge solenoid, and as I was takin it off, I decided to see if charcoal was in it again. Sure enough a whole bunch of charcoal bits came out. Now I know for sure, I need a new canister. I replaced the evap solenoid again with a new one, just in case, and cleared the code. Now The question is, Can I leave the purge line from the canister, disconnected? Does the PCM actually detect fuel vapors from the canister? Or just vaccumm? No, Im not trying to bypass the canister, just I have no money right now. I figured If I leave the line at the back of the car going to the canister, not hooked up that goes to the solenoid, then It can't suck in anymore charcoal. It would actually just be sucking in clean air, I thought about putting a small filter on the line temporarily, but wanted to know some more info, before I do something, I shouldn't. But will I still throw a SES light? Is it really reccomended to use a junk yard canister?

Thanks.

 

When you saw charcoal falling out of the canister connections, it was obvious it needed to be replaced. You have absolutely no way to know if a junkyard canister is any better or worse than the one you have.

You can leave the line from the canister, that attaches to the vacuum detection switch, off temporarily. But you have to cap the connection on the detection switch with a vacuum cap. Otherwise, you will have a vacuum leak every time the PCM opens the purge solenoid. If you do it this way, you shouldn't get a code.

You didn't need to buy a new solenoid either. Just open it up by putting 12V across the pins and blow the charcoal out with air.

 

thanks for the info injuneer, I know I didn't need a new solenoid, but they gave me one for free, since It comes with a 1 yr. so I figured why not. I actually didn't know if charcoal was supposed to come out of the canister or not, as I really couldn't find any direct info on canister malfunctions, ect... The parts places around me, made it sound like canisters never go bad. I'm going to cap off the line, until I can get a new canister, just wanted to make sure I wouldn't cause any damage before I did it.