Evap codes 0442 and 0455

Hi, We have a 2001 Gr Cravan with a 3.8. The check engine light is on and I am getting 0442 and 0455 codes relating to the evap system. I have been over the lines several times. I check the fuel filler tube, it was rusted outside but I could not find any holes. I feel like I am looking for a needle in a haystack. Any ideas would be appreciated. I am afraid without a smoke machine I am not going to find anything, wish they made smoke in a can you could hook up to the evap service port, but haven't found it yet.

Oh of course when it first came on I put on a new gas cap. If I unhook the battery it stays off for about 3 days or so, maybe I will just put on a quick disconnect on the battery LOL.

Any ideas are certainly appreciated, thanks.

I have the same codes and cannot pass inspection until I get the problem resolved. I also got a "1684" code. If I go to a mechanic, I'm probably looking at $200-300 minimum. Any info is appreciated.

Here is what I found:

P0442 Code =

EVAP System Small Leak Detected Conditions: ECT Sensor from 40-90°F and within 10°F of the BTS input at startup (cold engine), fuel level more than 1/2 full, engine started, EVAP leak test enabled, and the PCM detected a leak greater than 0.040 but less than 0.080" somewhere in the EVAP system.Possible Causes: EVAP fuel tank or canister vapor hoses leaking or damaged EVAP system component leaking, damaged or has failed Fuel tank cap is loose, or the cap release pressure is incorrect Leak detection pump damaged or leaking.

P0455 Code =

EVAP Large Leak (0.80") Detected Conditions: ECT Sensor from 40-90°F and within 10°F of the BTS input at startup (cold startup), fuel level more than 1/2 full, engine started, EVAP leak test enabled, and the PCM detected a leak greater than 0.080 existed somewhere in the EVAP system.Possible Causes: EVAP fuel tank or canister vapor hoses leaking or damaged EVAP system component leaking, fuel cap loose or missing Leak detection pump damaged or leaking.

The 1684 code just means the battery has been disconnected within the last 50 start cycles.

Don't worry about 1684, it is just a code that your battery was disconnected with in the last 50 start cycles. So that code isn't an issue. Here is a thread to read that may also be helpful:

http://www.obd-codes.com/forums/630-obd-codes-2001-dodge-grand-caravan---codes-1684-p0442-amp-p0455.html

Just a bit of info. You should not disconnect the battery to turn of the check engine light. I read somewhere that it can actually cause damage to something. I cannot remember all of the details. The correct way is to use the code reader to turn it off. No help for your issue- just a bit of info!:smooch:

Artic Cat..did you ever get this fixed. a thought: if it started with a new gas cap..maybe the new gas cap is the problem? Maybe you can get one from a Gas station...lot's of them are left behind... just go in and say I was here last week and think I might have left my cap...they'll pull out a box of 'em and you can grab one that matches yours.

If it's not the gas cap..you need to check the vacuum lines that are in the evap emissions system. There should be a sticker under your hood that shows the emissions hose routing..that can help.

My 97 GC has the Leak Detection Pump mounted underneath the van almost directly below the drivers seat, it sits in a cradle it's very close to the ABS system. There are 2 hoses to the LDP one is just an intake line that sucks air in when the pump cycles (to build up pressure) and one that connects to the carbon canister. There is a hose that runs from the carbon canister up to the purge solenoid valve which is a funny looking thing l4 inches or so tall that is shaped like R2D2. It's mounted in the engine compartment on the passenger side wheel well) a second hose runs from the purge valve to the intake manifold/throttle body....all of these hoses need to be air tight/able to maintain a vacuum If you have a vacuum pump you can check 'em out pretty easily...someone in another post fround that the vac line from the purge pump to the intake manifiold was cracked. There are also a few little rubbber boots/connectors that can dry-up and crack etc. It's really fairly simple to check

Hope this isn't TMI.

Spit

No I haven't fixed it yet. I have spent time looking over hoses, both above and below. Knowing full well it is pretty easy to miss a small leak. Course as you mentioned it can also be in a component of the system such as the pump, canister or purge pump failing, I don't want to just start replacing parts.

oh just to be clear, I replaced the gas cap after I started getting the codes, not before, just figured it would be something easy to try.

I really appreciate the post. I never thought about checking the intergrity of the lines with a vacuum pump. I don't have one, but we have a local harbor frieght and might be able to pick one up cheap enough. I'll have to think if I have something to create vacuum laying around. Would just need to take the time to work through the lines.

I suppose that instead of creating a vacuum I could use a light pump and see if I can find leaks in lines by creating pressure. I would only be able to test lines that way because the evap port cautions against pressurizing more than one PSI.

Thanks for the idea, I was thinking about just waiting until we got caught up on money (like never :banghead: ) and taking it to a garage with a smoke machine to find the leak. Like I said it seemed like I was hunting a needle in a haystack since it could also be a component. I tried checking everywhere thus far that someone has suggested.

Your post gives me another approach to finding the leak, thanks.

Artic Cat,
The good thing is that these codes really don't effect performance so if it takes a while, although agrivating it's not dangerous or damaging to the van.

That said...yes Harbor Freight does sell vac pumps. They handle MightyVac which is a brand name unit...for about $30 that's the one I have it comes with a lot of adaptors and small pieces of hose...they also sell a non brand name unit for $20...and it seems to made out of more metal than the Mighty Vac and may be as good or better. You can use these units for bleeding brake lines too.

If you disconnect a hose at one end...say the purge valve and hook up the pump...pump it to a vacuum and see if it holds..if it does, try the next hose/fitting. In some cases you have to block off the end of the hose to make sure it's air tight etc.

Can you tell if your purge valve is opening & closing...if you energize it with 12 volts it should open...however if for any reason the valve sticks in the open posotion (it's normally closed) it would throw a leak code. You can jump the pins on the valve to test it.

I would be careful pressurizing the system with compressed air..you might damage something. When Shops do that they use some pretty expensive equipment and I think they use 2-5 p.s.i. or less. Too much pressure might screw up the diaphram on the Leak detection pump, cause damage to the carbon canister and who knows what else.

One other thought... did you do a search on the Caravan Forum of AF for these codes? I know I have read some success stories..might give you an idea or 2 of where to look.

Good Luck

Spit

Thanks for the info, yea I really haven't been sweating getting this fixed, it bugs me and I want to get it fixed, but just been looking at it when I get a chance.

I did search the forum but really didn't find many clues.

I am definately going to get a vaccum pump and go after it that way. Not sure when I will get to harbor frieght but that sounds like a good approach, thanks for the info. I will post results whenever I find it.