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.
'09 E90 M3 | VF620 SC tuned and coded by BPM | KW V3 | ARC Wheels w/AD08 | OnEighty Lights | AA Signature Exhaust | BMW Performance and IND trim | Recaro Profi and child seats
'13 35i M-Sport X3 | JB4 Stage 1 | BMS Intake | H&R Springs | Gloss black grill | CF Wrap and Coded by me