Can I just undo the bolt on the altenator and tighten it? Or do I need to undo the power steering belt first? I know when you're replacing them you have to do them in order, but I'm not sure about just tightening one. D16y8 motor.

 

Probably worded this question wrong. What im asking is; Do I need to loosen the power steering belt before adjusting the tension on the alternator belt?

 

you do not have to touch the ps belt.

 

No, you don't need to. You can adjust them independently.