Okay to start off, I am new to the forum so hi to everyone and I look forward to being a member. I have a little problem right now with a mustang I recently purchased. The car is an 07 shelby gt that was in an accident and I have fixed back now. The car would not start when I purchased but upon further inspection someone had a blowwer on the car previously and they had pulled the tune and not replaced with factory tune. The Shelbys as U all may know come with a more aggresive tune from the facory and when the dealership flashed mine they used the stock gt tune. All is well and car starts right up but is throwing the dreaded p0171 and p0174 lean on both banks codes. I cannot find any vacuum leaks and engine runs fine once over 2k rpm but when u mash the pedal at idle it ust hesitates and almost dies before catching itself. Would anyone know if the shelby upgrades would cause this much touble with the factory gt tune or my problem is elsewhere? Thanks and all help is appreciated