We always offer free advice through a phone call or email. The biggest issue is the blanket chips for injector size 6xx. The late style injector started out as a 555cc, but the fuel ratios were pretty far off.....Because of this the injectors were tested and surprise a 615cc number showed up and new tuning......Well the injector continues to more in size now your saying it suppose to be 608? Well you can imagine through all of the moving around it is going to be a miracle if a real reasonable standard chip exists for such an injector. For anyone that has 6xx injectors, I suggest getting the car custom tuned. Of course this is always the best idea anyway.