I think I have a vacuum leak after my AFM, most likely where the TID meets the turbo, since i've been having trouble with that area before. My question however is, would a leak somewhere after the AFM cause bad readings and make the car run rich? Or possibly lean? Or would only a gigantic leak cause any trouble?

 

Should make it run lean. Unmetered air getting into the system.

 

Dangerously lean? Its not a big leak, because the car still runs, but idles a bit low and bouncy.

 

I dont think there is such a thing as "Safe lean." I was just taught LEAN = BAD and LEAN = POP (and not from your exhaust which is OK)

 

Lean is only dangerous at high load, because it causes very high combustion temps.

At idle the airflow is so low that even a small leak leak causes mixtures to be significantly leaner than ideal, which causes the poor idle. At higher airflow the leak is inconsequential because the proportion of unmetered air getting in is tiny.