If your headlights go low on idle and brighten up when you rev the engine its good to check the alternator. I'm sure you checked the obvious like a loose alternator belt. I don't know how sensitive the Bosch FI is to voltage drops but the Delco management does not like it one bit. When my alternator went out on my old SE my engine acted really weird and it backfired when the voltage dropped. I called my wife to bring a spare battery so I could drive the car home. It ran fine the 2 miles back to home with the spare battery. When I had the alternator fixed car was fine after that. Maybe the Bosch reacts the same way.
When I have to change out my alternator on this one I think I'm going over 100A because of the added electrical load on my car
When I have to change out my alternator on this one I think I'm going over 100A because of the added electrical load on my car