2003 Dodge Caravan, 3.3 FFV. CEL w/ code P0455. Took it to dealer. They ran forced NVLD test and found NVLD failure and replaced(NNN) NNN-NNNND Pump-Leak Detection. Two days later CEL back on with same code. When I took it in I also explained that when I first start the engine in the am it was evident there was a vacuum being applied to the fuel tank because you could watch the plastic tank collapse, then after about 1/2 mile there would be a pop and it would be back to normal and CEL would stay on all the time. When I cleared the code it would take 2-3 days for it to come back on and then the vac scenerio would start. Any ideas? Do you think the leak detection pump was really bad?
Dodge Caravan 3.3
Dont think the pump was bad you either have a plugged charcoal canister, filter or gas cap.
7 years experience, ASE master certified, electrical, chassis, and powertrain master
I had already replaced the gas cap with a new OEM cap. How could a plugged cannister or filter cause the P0455? That possibility does not show up in the trouble tree for that code?
Your tank is getting sucked in and the canister or filter is plugged not letting the vaccume out.