Fuel tank leaking from top of tank. I noticed a white, large twist on cap that was a little loose. Cap has two hoses attached to it, one valve looking thing w/ no hose on it and a small capped attachment.

SOURCE: 03 grand caravan ex 3.8. check engine light - code

Customer Concern: MIL on and code P0456 for a leak in the evaporative system. How to test the Leak Detection Pump (LDP). Tests/Procedures: 1. With the engine running, connect a test light to the Violet/White wire at the LDP. The test light should light.

2. Ground the center wire at the LDP. The test light should go out. This is the intake stroke of the pump. The LDP pulls in fresh air when the center wire is grounded with a vacuum supply to the LDP.

3. Remove the ground from the center wire and the test light should light up again. The pump has just pumped air into the evaporative system. The test light lights up when the diaphragm is in the down position.

4. To test the LDP for leaks, cap off the port that goes to the canister or to the vent valve. This is the port that is slightly above the bottom port that goes to the vent filter.

5. Now try to cycle the LDP again by grounding the center wire. The test light will still go out but now when the ground is removed from the center wire, the test light should remain out for at least 20 seconds if the LDP is good. Potential Causes: Leak Detection Pump (LDP)
Vent Valve

Duane Wong

• 6826 Answers
• Posted on Jul 22, 2010

SOURCE: 01 dodge ram 3.9 moter check engine light

Did you clear the code after replacing the gas cap and cracked hose?
You can do this with an OBD-II scanner from Walmart which costs under $100, or have the auto parts store do it that you bought your parts from if they are willing.

SOURCE: 2000 Dodge Dakota sport truck, check engine light

Here is a TSB that includes P0455. Sometimes leaks are hard to find. I found some I would have never found without a smoke machine. When you looking squeeze the rubber hoses crack show up better. Check the hoses good by the batter.

SOURCE: This error code p0457, just

The bad gas cap is related to the evaporative emissions what happens is the gas that is not used in the engine return to the tank via the 2nd hose. The tank is pressurized very lightly by this and a sensor detects whether or not the air escapes. So if the cap is loose or there is a leak in a hose the code will set. Since you also have a leak I would start there first. The straps most likely are not cutting the tank the epa would have a fit. Most likely the the gas is coming from above the tank and working its way down the straps. Lowering the fuel tank requirs raising the car quite high. If you are able to inspect the area and reach it I think the leak would be in the gas lines above the tank. Or from the filler tubes when you fill with gas. If you can see the gas leak but are unable to reach it take it to a shop. This may fix the light if not a shop with a (smoke machine) will pump smoke into the system and search for air leaks that way. Good luck .

SOURCE: 2001 Dodge Caravan did not pass emissions due to

may have cracked vacuum lines.