Conversation Between TAILWAG and aer

in theory yes, but since they are all connected, they will all throw the same code. The actuator is the easiest to get to, the cam sensor is 2nd easiest and the cam, obviously, is the bad one which you don't want to mess with.

I am going to do a durmatic scan before doing anything. That should tell me if it is the actuator, the cam or the cam sensor

I don't think it is necessary to do that, but, there is a possibility, that, when you replace one, the other side may be working harder, and could potentially fail. This may take a few miles, hundreds, or thousands. I don't have an airbox - I have 2 intakes on each side by the intercoolers as I am heavily modded. The airbox is fairly easy to remove however, so it is held by 4 bolts from what I recall. I am sure there is a link if you search that shows the bolt points. Good luck man.

Hi-- My 2009 TT just threw a p0021 so I will replace the actuator. In your opinion should you replace both banks at the same time? The car has 29k miles on it. Also, how do you remove the airbox to get at the 2nd actuator. Thanks