How to repair intake manifold runner control

@ecjones3rd surely you already checked to see what your error code P1518 covers

Faulty Intake Manifold Runner Control (IMRC) actuator

Intake Manifold Runner Control actuator harness is open or shorted

Intake Manifold Runner Control actuator circuit poor electrical connection

Faulty Powertrain Control Module (PCM)

So you do want to start by checking the connections, wiring and clean any potential corrosion etc from the connectors. After that you want to check places like this and see if that will help you further. You have to investigate a bit on those parts since the error code is not telling you to specifically change/repair one part.