Evap. System Leak (p0456) ?

[JeremyCampbell]

The light on the dash came on. My wife took the mini van for a reading at an auto store and reads

" p0456 Evap.System leak detected(very small leak)"

Questions:

1) Could it just be the gas cap not sealing?

2) Are the leaks more just vapors that arnt really effecting the vehicle but more an emissions/environmental thing?

Thank you

[fishhuntwork]

I use to see these all the time on Chrysler Miivans. The were usually a few things: Gas cap, a hole in a rubber hose, gas tank, or the eval purge pump. The only good way to test them in with a smoke machine to find out the issue.

[JeremyCampbell]

I don't know if this all is related but there is also a couple of other things we noticed.

1) Gas gauge doesn't work well.Gas gauge will show over a quarter of a tank , then the gas light will appear and say it's almost empty.

2) When filling gas it always seems to click when there's only a small amount of Gas in the tank.We reposition nozzle many times with same results.

3)Had the fual rails replaced a couple months ago.The gauge malfunction and the clicking were already a problem before the fual rails were replaced.

[JOHNBIGDOG]

The light on the dash came on. My wife took the mini van for a reading at an auto store and reads

" p0456 Evap.System leak detected(very small leak)"

Questions:

1) Could it just be the gas cap not sealing?

2) Are the leaks more just vapors that arnt really effecting the vehicle but more an emissions/environmental thing?

Thank you

1) directly, yes the gas cap could be a leaking. Is this always the case? no. It would be a good idea to have someone smoke test it to find the leak. As you describe that the fuel pump kicks off when you fill it up is also a symptom that the evap vent valve may not be working properly.

2)Evaporative emissions can affect fuel economy some. The car stores evaporated fuel vapors in a charcoal canister. When the Powertrain control module deems necessary it will suck those vapors out of the charcoal canister and combine the vapors with the intake air. This extra fuel would have been wasted to the air, but the car is able to burn them increasing fuel economy. Will your car not start because of it, no. Should it be fixed? Yes. no one likes to see the "Check Engine Light" on.

[Jeremy airjer W]

Year, Make, Model, and Engine Size?

While I agree with smoke checking there are some "normal" things to look for on specific years.

On the later models there is a short piece of rubber hose under the air filter on the passenger side that likes to crack and throw this code. It is about 3" long and connects the plastic line from the purge solenoid to the metal line that goes back to charcoal canister.

On most models a thorough inspection of all the rubber hoses, especially the ones near the charcoal canister, may reveal a cracked hose. These will look like hair line cracks and may not show up unless the hose is slightly flexed or deformed.

[JeremyCampbell]

2002 Dodge Caravan V6 3.3L

The van works fine, its just these stupid gas related things.Thanks for your help everyone.

[FF_205]

being you said that when filling your tank the filler will click off, It seems to me that your charcoal canister is plugged with dirt. When you fill your tank the air in that tank need to go somewhere, when the vehicle is off,( key and engine off) there is no power going to the canister vent valve, keeping the valve open, allowing the air in the tank to escape through the canister and threw the vent valve, when dirt and gravel get into the canister, it plugs up and doesn't allow the air to travel through, causing the gas to back up in the filler neck and clicking off the nossel. Also if there is dirt and gravel in the vent valve it will not seal and also cause a Evap leak. Like said above, having a smoke test would find this issue properly

[Jeremy airjer W]

being you said that when filling your tank the filler will click off, It seems to me that your charcoal canister is plugged with dirt.

Unlikely on this model....

The NVLD (natural vacuum leak detector) which acts like a vent solenoid, has a filtered breather. If no vacuum leaks are found than the likelihood of the NVLD being the cause of the problem is VERY likely. These are a known issue across the Chrysler brands