Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
It sounds like there may be just a bad fuel tank pressure sensor, or connection at it. Here is how it can be tested, along with the description and particulars of the code setting.
CIRCUIT DESCRIPTION The Powertrain Control Module (PCM) monitors the Fuel Tank Pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the enhanced Evaporative Emission (EVAP) diagnostic The PCM supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases as the fuel tank pressure decreases (negative pressure or vacuum, high voltage). The FTP sensor signal voltage decreases as the fuel tank pressure increases (positive pressure, low voltage). This Diagnostic Trouble Code (DTC) sets when the FTP sensor signal goes below a predetermined value.CONDITIONS FOR RUNNING THE DTC The engine is running.CONDITIONS FOR SETTING THE DTC
ACTION TAKEN WHEN THE DTC SETS
CONDITIONS FOR CLEARING THE MIL/DTC
You will want to make sure of the connection at the fuel pressure sensor, (1) and related wiring. Or, the sensor might just be bad.