I have the engine management light on in my 2002 ST170

Had the snap-on machine report two faults


P0420 - Catalyst system operating outside range

P1518 - Intake Manifold Runner Control Solenoid Stuck Open

Has anyone else had this fault? Where is this manifold control solenoid? I'm assuming it has something to do with the variable tract length.

I'm also hoping the catalyst fault is just a knock on from the solenoid problem.

Any help appreciated