They are correct. A catless x-pipe will get you the best gains for the buck. Tuning it will get you additional gains and rid of that SES light.
Now I could also get an additional 40-50 hp by moving to the east coast down to sea level and running 93 OCT.
'13 35i M-Sport X3 | JB4 Stage 1 | BMS Intake | H&R Springs | Gloss black grill | CF Wrap and Coded by me | Recaro Child Seats
'15 M3 DCT AW/SO | JB Stage 1 | RKP Diffuser | P3 | M Perf Spoiler | iND Exterior Trim | Recaro Child Seat