Have you ran the codes?
Have you cleaned the MAF?
Last time you did a full tune up? Plugs, wires, cap, rotor, fuel filter.
What is your fp like?
Check for vacuum leaks with some carb cleaner everywhere.
2016 VW GTI 2.0 Turbo
1989 Sonic Blue LX Coupe, 349 ci, TW heads, TFS Track Heat Intake, 75mm Accufab TB, 80mm ProM, 30 lb. inj, TKO, 3.73, 31 spline w/ TruTrac, MAC 1-5/8" LT headers w/ H pipe, Flowmaster, electric fan Moates QH
391 rwhp & 424 rwtq...Mustang Dyno 11.5@122mph