I just have one thing to add. Not all of our cars have two fans. Mine has only one fan but it has two different speeds that it operates at. That is all I need.
BTW, My car has a whistling sound too. But that is probably my intake. lol. The car bogging down in normal. The whistling I have no idea. I'd have to hear it. Why don't you listen to the car while it's running and see if you can't figure out where the whistling is coming from. That could help out a lot.
