What your ROM cells say and what the ACTUAL AFR is....is a different story. The oem tuners may have had to command a 9.5 AFR to get a 11.3 AFR at the o2 sensor location. At least thats how my rom is. Ive got a 10.5 afr commanded at full boost 5000 rpms and up. Its running about 11.3-11.7 actual afr tho.