2000 S4 with APR chip 12-13 PSI on the highway

[Fiyacracka]

I've been having this problem for over a month now and it's driving me insane! The car was running absolutely mint before and all of a sudden the car feels very sluggish. I noticed that I get anywhere between 16-18 in 3rd and 4th. But once I get on the highway it only boosts 12-13 and it feels like I'm going nowhere in WOT. I've smoke tested the car and didn't find any leaks. Here are the parts I've changed this past week: N75 - brand new N249 Put forge 007 Diverter valves TBB O2 sensor (mine was lazy, no CEL just a code every time I scanned it) Drivers side intercooler (mine looked like it was soaking, so I changed it) Mass airflow (Bosch) brand new (I have a spare motor so I just started throwing things in) I am running out of ideas. Any help would be really appreciated!