Sometimes, my 1.8t has a hard time idling after coming to a stop. It seems to act like the idle control valve is bad. But, in looking at it, it doesn't look like it has one. What would be the cause of this?

 

I thought only the V6 had an ICV.

Things to check:

Vacuum hoses (replace them if they are looking cracked or dry).
MAF sensor
Leaks around MAF housing
Get new sparkplugs
Do a throttle body adaption
VAG your car

 

Does it do the RPM "bounce"? if so its just your computer relearning your car. its perfectly normal and will returnn to normal in a day

 

He said "sometimes", which leads me to believe it is a cronic problem. But you are correct, the idle will bounce while the ECU is adapting (~100 miles) after a battery disconnect.