The signal for the gauge comes from the sensor to the ECM and then to the dash gauge.
I would remove the connector and test for 5 volts to the sensor and also check the return voltage as well.
Based on what you have done, it sounds like you may have pinched the harness when installing the intake. Look at the back of the intake and make sure the harness is free and not damaged.
The Cylinder Head Temperature (CHT) sensor:
is mounted into the wall of the cylinder head and is not connected to any coolant passages.
sends a signal to the powertrain control module indicating the cylinder head temperature.
if the temperature exceeds 126 C (-258 F), the powertrain control module disables four fuel injectors at a time. The powertrain control module will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine.
if the temperature exceeds 154 C (310 F), the powertrain control module disables all of the fuel injectors until the engine temperature drops below 154 C (310 F).
DTCs are set.
If the engine reaches critical temperature, the following happens:
The coolant temperature gauge pointer will read fully hot at 121 C (250 F).
Tuesday, August 4th, 2020 AT 5:09 PM