Anyone know what this is? EVAP system.
Another view:
Looks like it is the gas tank vent valve, busted, and it should go in the hole in the brake line bracket hole indicated by the arrow. But the drawing in the manual looks different? Generic drawing maybe?
So is this the gas tank vent valve, anyone have a pic of what a good one looks like? I'm thinking it might be the root cause of the code if it is the vent valve.
Anyway, parts stores don't carry it, didn't even know what it was, not on their computer. So went to dealership, they didn't even have it, had to special order, be here next week. Will post a pic for future reference when I get it.
And this is what it looks like installed:
When I crawled under the car to do the work, gas smell was heavy, courtesy of the busted valve. Glad nobody tossed a butt under there before I found the problem.
.
With the car lifted, is it visible and out in the open? Is the evap purge canister nearby? Is the canister hard to replace yourself?
Where did you buy the vent valve from? I tried searching for it on eBay, but nothing.
There is a seperate vent assy for the evap cannister. Rectangular looking thing sitting on a bracket under the front of the gas tank, behind the axle on my 98. I removed it to test the valve with 12volts just out of curiosity to see if it was functioning, as long as I was down there. Here is a pic of it:

Cannister is behind the cover behind the driver's side wheel. I tried to pop it off when I had to replace the rotted clamp, but couldn't. The drawing in my manual makes it look like it clips onto a bracket, but I couldn't figure out how to do it. Had to do the clamp while it was still installed and it sucked. You can remove the surround from the tank filler neck and have a look at it thru there. Just don't use a drop lite with a bulb or you might go boom.
I didn't find any trash in the cannister purge valve (located on intake manifold, driver's side), so didn't think cannister was fubar, just needed a new clamp.
Got the gas tank vent valve at the dealership, had to be special ordered, ~ 25 bucks. Gm parts direct lists it for 13, but they have a rep for raping you on shipping. Search 10245442 here: http://www.gmpartsdirect.com/
That is the pn that came up at the dealership when he entered my VIN, your car may take a different pn.
0440 gone, along with the occasional whiff of gas smell I used to get.
Last edited by angel71rs; May 13, 2008 at 08:43 PM.
Trending Topics
I've got a P0442/0440 code that I want to get rid of. I've already replaced the gas cap a while ago, so that's elimitated. Now that I know the vent valve is visible from the bottom, I'll inspect it the next time I have the car lifted up. I'm gonna hold off getting a new vent valve until I confirm that my current one is damaged, so I don't risk wasting the $25. At the same time, I want to inspect my purge valve. Do you remove the purge valve by just pulling on it? And do you also have to remove it from a specific end first, or is it detachable at both ends?
Would you happen to know the part number for the canister? I couldn't find any references under a description search on Yahoo! or eBay.
Thanks again.
The Best V8 Stories One Small Block at Time
Tap it on something light colored to see if any crap falls out of it; that can mean the cannister is falling apart internally allowing crud to get sucked up to the purge valve.
I also tested the valve with 12 volts from a small power supply I have and a lenght of speaker wire with the ends terminated into red butt connectors (perfect for sliding onto connector pins without shorting). You can hear and feel it click; polarity not important.
Don't have PN for cannister, but you can try the "catalog" tab at gmpartsdirect.
Heads up on the gas cap: my research into evap codes lead me to a thread in which some guy said a gas cap he bought at a parts store was defective. Around here inspection stations can test the cap seperately, maybe you can have it checked if you can't find something obvious like my busted tank vent valve.
Last edited by angel71rs; May 14, 2008 at 09:42 AM.
I had the car lifted up yesterday, and I couldn't find the the white vent valve at all! I looked all over, and just saw bunched wires running along the area with nothing clamped onto the bracket where your vent valve is clipped onto. Then, when the technician called the dealership about it, he was told that if the vent valve isn't at the bottom, it'll be located above the gas tank. I figured one of the previous owners might've modded this part. Of course, the other possibility is that it was removed altogether! I took a picture with my phone, and will post it up later if I can figure how to send it with the Chocolate phone (I'm used to the Razr).
I see you drive a 98 Z28. Mine is a 99 TA. Were the vent valves placed differently between the F-bodies of this period?
My car's got the same bracket as yours where the white vent valve is clipped onto, except I don't have a valve OR a line for a valve to connect onto!


Could someone have removed this vent line and valve entirely or relocated them? What purpose--if any--could there be for someone to remove it?
And this is what it looks like installed:
When I crawled under the car to do the work, gas smell was heavy, courtesy of the busted valve. Glad nobody tossed a butt under there before I found the problem.
.
Is there a new part number for it, or is there some other type of valve readily available I can use instead? I'm a little stumped on this one. Thanks in advance!
I'll have to make some phone calls to some dealerships tomorrow. Thank you!
Called a dealership yesterday, and had them do a nationwide search. The part was unable to be found anywhere nationwide. I've called some junkyards to find the part, and was unsuccessful. Needless to say; I am not having fun finding this damn part.
Anyway - Classic Industries sells a similar part for older cars and its only a plastic housing with a cotton ball stuck in it. If that's the case, I'd totally trust one purchased used from a yard. (The one Classic Industries has is just the housing - the owner has to supply their own cotton ball!)


