2003 P0441 and HIGH Pressure in Gas Tank? Evap Leak Det Pump?

[Mr L]

2003 Liberty 3.7 We are getting high pressure built up in the gas tank. And getting a P0441 "Evap System Incorrect Purge Flow". Jeep runs Ok but keep setting the CEL and code. The early KJ's are different from later in the emissions layout. From what I can tell we will have to drop the tank to replace the Evap Emissions LDP01 Fuel Vapor Leak Detection Pump (inage below)? Gas cap is new. Evap Canister Purge Valve is new. ??

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