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May name is Dave and I will try to help you today.
The fuel tank pressure sensor is very sensitive to pressure changes. It is possible that a leak was made during the installation of the new FTPS. did you use any sealant when installing the sensor?
Also, as far as your original issue, was the gas cap checked/replaced? If the vent in the gas cap goes bad, it can cause the PO0453 code (or the PO452 code if it fails open).