[Patrick Lang]

I'm stuck.
I had "gascap" come up on my dash which turned into a check engine light.
Pulled the codes and got P0455 and P0457.
I do a smoke test and i'm finding nothing. Gas cap is fine
ANYONE ever have this problem? If so what was your fix?

-2011 Dodge Nitro Heat 3.7L RWD

 

[Stevenitrosublette]

I just last week posted mine thru P0456 small Evap leak . All I did was clean the sealing edge of the fuel filler tub and I replaced the gas cap with a new OEM cap. Cleared the code and it hasn't returned since .
I clean the surface with some Scotch brite and Acetone.

 

[Scar0]

P0455 Evaporative emission (EVAP) system - large leak detected. Possible causes; Hose connection(s), intake leak, EVAP canister, EVAP canister purge valve.
P0457 Evaporative emission (EVAP) system - leak detected. Possible causes; (filler cap loose/off) Mechanical fault, hose connection(s), EVAP pressure sensor.

Smoke test showed nothing at the canister, interesting.
Check for a loose or cracked vacuum hose, and the purge valve next to the battery.

 

[Patrick Lang]

P0455 Evaporative emission (EVAP) system - large leak detected. Possible causes; Hose connection(s), intake leak, EVAP canister, EVAP canister purge valve.
P0457 Evaporative emission (EVAP) system - leak detected. Possible causes; (filler cap loose/off) Mechanical fault, hose connection(s), EVAP pressure sensor.

Smoke test showed nothing at the canister, interesting.
Check for a loose or cracked vacuum hose, and the purge valve next to the battery.

Purge valve is good. I looked all over at the vacuum lines and didn't see any cracks. I checked around the filler neck and got nothing. Gas cap is brand new. I was think it might be a faulty leak detection pump?

 

[Stevenitrosublette]

If nothing else Patrick, that's where you could start . Did you pull the purge valve off and check vacuum in both direction when energized ? It should hold vacuum in Both Directions.

 

[Patrick Lang]

If nothing else Patrick, that's where you could start . Did you pull the purge valve off and check vacuum in both direction when energized ? It should hold vacuum in Both Directions.

Yes i did. Im gonna start with the leak detection pump.

 

[Stevenitrosublette]

Keep us updated please . I especially want to know what fixed your Evap in case mine comes back . Thanks

 

[Scar0]

One would think a large leak would be simple to find. But, things do not always go according to what one thinks...
Please do keep us posted. It sounds like you are on the right track. It's just a matter of finding it.

 

[Patrick Lang]

Still found no leak. But last week when everyone paniced about a gas shortage, i took my factory gas cap back off and put my lock gas cap back on. After i did that, the next morning the gas cap light came on and i cleared the code before i left for work. When i left work the light didn't come on. It has still yet to come on. Idk what is going on with my Nitro

 

[Scar0]

... Nope got nothing...

 

[Patrick Lang]

Still no gas cap light and it's been two weeks...

 

[Stevenitrosublette]

After I got a Evap code I changed the cap no code since . It's been about a month . I think it was just the cap ?

 

[Metaldog]

A couple months back, I had my gas cap light come on while driving to work. Got to the parking garage. Checked, and the cap was loose. Tightened it down and was good for a couple days. Then my CEL came on. Did an OBD scan to find that the "small EVAP leak" triggered the CEL. Since I had already had a loose cap, I figured to start there. I went into the house and grabbed a Chap Stick tube. Pulled the gas cap off. Smeared a liberal amount on the rubber gasket and put the cap back on.
I intentionally did not clear the code, realizing it would probably go away on its own. A day later, the code had cleared itself out. Have had no issues since.... Knock on wood!

 

[Stevenitrosublette]

Like I did too , but I cleaned the sealing edge and bought a OEM gas cap . No problems since .

 

[Patrick Lang]

Like I did too , but I cleaned the sealing edge and bought a OEM gas cap . No problems since .

I did nothing but put my aftermarket lock gas cap back on and the light has still yet to come on

 

[Perezinnes]

Does the evap. Solenoid have power going to it and if it does were is the fuse for it mine don't have power only ground when you plug in the solenoid then it has ground on both sides

 

[Scar0]

Does the evap. Solenoid have power going to it and if it does were is the fuse for it mine don't have power only ground when you plug in the solenoid then it has ground on both sides

Purge is not grounded as one might expect.
Pin 2 is control wire from PCM, Pin 1 is return wire to the PCM. The current is monitored by the PCM computer.