Hi All. Maybe someone can shed some light on a problem I'm facing. Basically i am helping a friend tuning his volvo v70 180 bhp stock 2.0 with mE7 ecu, having a 16T turbo, blue injectors and a standard Maf sensor. The problem is, during open loop conditions, car runs good, in fact it gave us 240bhp at 1.1 bar boost lambda 12.3 AFR on 98 gasoline. Problem is after 30min driving, or sometimes less, where performance becomes sluggish and it settles at 200bhp,lambda goes at 13.8-14 AFR, and boost remains 1.1 bar. logged the car during the poor performance condition where timing stays the same (12 dgres at WOT), so no knock occurs. LTFT almost to 0 (-7 minimum), and high lambda. Today i noticed that MAF, at 1.1 bar reads maximum 156gs. I remember that on stock turbo, maximum Maf was 150 gs, so basically, MAF is almost reading the same values also on standard turbo. Car has a sports CAT installed, could be high back pressure causing low inlet airflow? Also, MAF housing is not changed. We only upgraded the MAF tubing that goes on the turbo that has same diamter. Could be MAF limit? I tried to search what is the maximum air flow that the stock maf reads but with no luck. For your reference I uploaded stock and mod file of the Car. Also i didn't try to change the MLMAX.
 Thanks in advance