In the service manual, expand "Engine / Hybrid system" to "FA20 ENGINE CONTROL" to "SFI SYSTEM" and then open up the P0451..0453 page:
https://gt86stuff.onrender.com/t3Portal/
It's got a series of diagnostic steps, which may be more detailed than expected - but, it does explain specifically what P0453 means: "EVAP pressure sensor voltage is 4.1 V or more for 1 second: If the canister pressure sensor voltage output (pressure) is 4.095 V: 108.99 kPa(abs) [818 mmHg(abs)] or more, the ECM interprets this as an open or short circuit in the canister pressure sensor or its circuit, and stops the EVAP system monitor."
It specifically calls out three causes:
- Wire harness/connector (ECM - Canister pressure sensor)
- Canister pressure sensor
- Open in ECM circuit
There's another forum post that talks about P0453 after a revert due to a wire being loose into the ECM:
https://www.ft86club.com/forums/showthread.php?t=136041
So that might be a useful first step to check.