I have an 06' STS-V pushing 569HP according to the tune shop in California that set this car up. I recently flagged a check engine indicating Bank 1 and 2 Lean condition. I checked the MAF and Vacuum lines but found no issues. The car has an oversized driver pulley for the super charger sheave and I am wondering if the dealership compromised my tune and set it back to the factory settings. With that said, do I buy HP tuner and go it alone with no experience what so ever or do I hire a professional tuner to verify which map I am using and then re tune the car. I have spoke with the shop in California and they are willing to send me the tune that they had on file for this car so it should be fairly easy to load the upgraded tune onto the car. Any suggestions? Does anyone know of a good tuner in Michigan? Should I go professional or put the time in and go it alone? I have an engineering background with general car knowledge but I am not a pro with custom map tuning experience! Any suggestions or comments are appreciated!