I just got the safc for my turbo ls installed it and tried to tune it but it's not making any difference what so ever. I have a missing link and a vortech fmu. it says in other threads to get rid of the missing link but when i took it off the map sensor threw a check engine light and I'm only boosting at 5psi. the air fuel is fine up to 4 grand but after that it goes straight to lean. am I doing something wrong? what else can I do?