3800 Trouble Code P0440

[rockbassray]

I got this code for the Evac Emission Control System, and have no clue what i need to do to fix this.. i have already double checked my gas cap to make sure it is one... i went to auto parts store they said it could .. a canisitor and that the dealership only has them... any help?

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[sgtp]

I got this code and it ened up being the purge valve under the hood that was bad. Its the litle black canister you see above the rear rocker cover. What happened was this purge valve seized up and failed to open to create a vacum in the gas tank during the emmisions diagnostics. I could have just got a new one, but after testing mine, I just loaded it up with wd40 and that got it loosened up untill is opened and closed freely.

Besides the gas cap, there also is a vent valve solinoid up behind the fender by the gas cap for you to check. I replaced that when troubleshooting my p0440, but I suggest you start with the purge valve under the hood.

 

[rockbassray]

Grest thanks!!. now is there any online pics of where exactly it is or looks like? cause i am not to svay on exactly where it is.. or where to look? 2000 gtp

 

[Dayride98]

Follow the vaccum line comming off of you throttlle body. Its right behind the SC.

 

[rockbassray]

Ok so i took this part off and sprayed WD40 in both sides of it for a while.. cleaned it up and put it back on.... check engine lite still was on....

... they should have cars that when a part is going bad it should say exactly what it is not... be so much easier to fix the problem..!!! I dont knwo what to do now.. it is not affecting the car at all just a very annoying lite on my dash... another thing is.. my low coolant lite stays on for about 15 mins then turns off i check the radiator and the reserve tank for it both have enough fluid in them... not sure why that is going bad?...

 

[sgtp]

well, you might want to try this before you replace anything. I recall having to rig some wires up so I could put 12 volts thru it while its off the car. At first it would just buzz, so I used more wd40 and continued putting 12 volts thru it (I mean on then off, etc). Eventually it started to free up some untill it opened and closed freely and completely. You will know this by the sound of it and the feel of it.

Dont get discouraged by this code. I fought this code for over a year and it kept coming back. I changed the gas cap, the vent valve by the gas cap....I even rigged up a shrader valve on my old gas cap to presurize the gas tank and look for leaks, but that proved nothing... It all came into focus though, when I found this purge valve wasnt opening. If you can prove to yourself that its opening freely but the code remains, we'll move on from there

 

[rockbassray]

cant i just go to the parts store and get a new one> easy to replace

 

[rockbassray]

is there a way to tell if it is working fine? i tried shaking to hear anything move.. and nothing was.. not sure if anything is supposed to.. and i couldnt find any way of opening it.. without tearing it apart.

 

[J.E.T.]

It's a $7-9 dollar part from Autozone if I remember right. Sometimes shotgun troubleshoting is the fastest and easiest fix.

The ses code wont go right away after the fix. You will have to clear it and then wait and see.

P0440 could any any part of the evac system - from purge valve, to lines, to canister.

J.E.T.

 

[sgtp]

Well, it is a GM part, expect 20 to 30 bucks at the dealer......I'd double check the number, but I think its 1997297. I spent more than 40 bucks on parts on parts trying to fix this code, but ended up fixing the defective part myself anyway. If you want to start replacing parts, at least start with the purge valve under the hood. Its most likely to fail , IMHO, due the the heat of the engine under it.

After fixing the problem, this code goes away after two key cycles, assuming you replaced the right part


heres where I found the pn: http://www.ilgpc.com/forum2/index.php?showtopic=439