JSmith

iTrader: (5)

My SES came on today so I a-tap'd it and that's the code I got. I did a search here and someone said it might be from a loose gas cap? I checked mine and it's not loose. I always turn it until it clicks. I've been setting the SES light almost every two weeks now and until today I haven't been able to check it since I got a-tap about 2 weeks ago. Anything else I should be looking into?

silent1

iTrader: (3)

I'm pretty sure that code refers to an EVAP leak. Usually it is gas cap related. Somtimes the gas cap itself isn't holding pressure or the o-ring is worn/torn. Another thing that is pretty common on most any vehicle is the purge valve sticking open. Check for aby obvious leaks in vacuum lines thruoghout your fuel/EVAP system. Have you had any body work done lately? I've seen some body shops actually drill small holes into fuel tanks before. Hope this can help you some, good luck.

JSmith

iTrader: (5)

I just and checked the cap again and although not completely loose it turned a bit before it clicked. The o-ring looks to be in decent shape on the cap. There hasn't been any body work done but now I think about it I've gotten an SES light alot more often since the tranny rebuild, not sure if it was this same code the times before the tranny rebuild though. Does this code reset itself?

silent1

iTrader: (3)

Reset itself as in clear itself? If that's what you mean, then yes it can but, only if there isn't a real problem. After it passes it's readiness drive cycles a few times it will clear itself. But, if there is a problem, the your SES light will continue to come on.

rgvsierra

iTrader: (7)

i got that code after i changed my fuel pump out, and its still there.

JSmith

iTrader: (5)

Just an update. I reset the computer and 8 days later (yesterday) I got the same code again and this time the gas cap was tight. What do should I start looking at now to correct the problem? Thanks for any help!

Tom@SpeedInc

iTrader: (5)

P0440 is evap malfunction, if your gas cap wasn't tight to the point of clicking (3 clicks is the torque spec, belive it or not) theirs a good chance that was the cause. If the fuel has been overfilled, it can be sucked into the charcoal canister causing P0440 but most the time any serious malfuntion of canister, vacuum leak, VSV etc will cause P0440 P0441 P0446 to all be shown.

sleepersilverado

iTrader: (1)

i know here in texas the inspection stations will some times take your gass cap and check it. so you might possibly be able to go to an inspection place and heve them chack your gas cap. that would be the easiest thing.

JSmith

iTrader: (5)

I know that the code is for the evap system. As far as the gas cap, yes it was tight both times I'd gotten the code. Also, the gas tank hadn't been over-filled. PO440 has been the only code both times I've checked. Could a bad cap be the cause? It "looks" to be in good shape. Maybe I'll get a new one tomorrow and see the problem re-surfaces.

chevy1500

i got code p0440 and replaced the gas cap, cleaned the tank vent solenoid,purge valve and hooked them up to 12v power and they click when supplied power. i have heard that if you over fill your tank that could cause the canister to go bad. i always put as much gas as possible in my truck so could that be my problem? it seems like the light comes on right when my truck reaches 3/4 of a tank. i took the canister off and no fuel came out it sounded like sand was inside, is that normal?