S4 full emissions delete, car is running very rich?
 

I've read on the FD if you do a full emissions delete, your tune is completely screwed after that and you need to go to a standalone ECU to get it running properly again. Does the same apply to an S4? Ported wastegate on turbo. This car has an Rtek Stage 1.5 to defeat fuel cut and let me run 10psi which it holds just about to redline.

The previous owner removed all emissions gear. Currently it has low idle vacuum (8-10mm/hg) but idles fine. It will hunt RPM very occasionally but only maybe 50rpm in each direction from 750rpm. I'm hunting down the vacuum leak this weekend, along with a possible boost leak or maybe dying turbo (odd sounds when at low boost when the car is warmed up).

But the tune seems very rich and the car is sluggish below 3000rpm or so. It is difficult to heel-toe the car and rev match properly because it needs a lot of gas for quite a while to get from low revs to 5k+ when it's in neutral. Is this due to the emissions removal, low vacuum, or something else?