I would start replacing vacuum hoses that seem cracked or are hardened from engine heat.
Then I would try to set the idle and ignition. You need to be in timing mode for this. Basically the ECU is continously regulating the amount of air coming in the engine by steering a solenoid which is the AAC. You might want to try to clean this too.
It can be a little hard doing this the first time but this are the cheap things to try before getting another AAC for example, since those aren't very cheap new. And getting a secondhand one which doesn't solve the problem isn't helpful either if you are not experienced with how the engine idles and why it needs this regulators (it wouldn't idle at all if it hadn't)
I'm not expecting a bad CAS or a bad MAF, however the latter can be pretty worn and also doesn't come cheap from the dealer. You might want to try to clean the MAF.
Basically you need to check all your sensors and indeed check for codes. Also download the FSM if you haven't already.