OldCowboy

I understand the latest version of the 2.0L TFSI engine has a 5th injector. I have a couple of questions about it:

1) Where is it located?
2) When is it active?

Buckwheat

You have been mis-informed. The new 2.0 TFSI has eight injectors, two for each cylinder. One injector is a direct injection unit that delivers fuel directly to the combustion chamber, the other delivers fuel into the intake manifold right behind the intake valve. Audi claims that this arrangement offers better engine flexibility and improved emissions, but I wonder how much the intake valve carbon buildup problems associated with recent direct injection motors played a factor. I know nothing about the mapping distribution for the two injectors, so can't address the "when is it active" part of your question...

Nostromo

He's referring to the new e85 compatible TFSI. It's got an extra injector to help with cold weather starting. I think they call it the "fifth" injector even though it's technically the 9th.