I got this 2003 tahoe that i picked up at ranch that has been sitting parked hasnt been used since 2014 put new battery changed spark plugs, oil + filter, all 8 ignition coils cause it had a misfire when i got it.. new fuel filter air filter new throttle body... flushed the transmission out new filter gasket change A+B shift sylonoids ecs.. well that didnt work still acted the same which is itll start in 1st gear go to 2nd wont go back down unless i shift it manually wont go to 3rd gear nor 4th Ive already changed the transmission out the new one acts the same as the old wel i got the ECM PCM ECU reprogrammed from Flagship1 online sent them my VIN I installed it did the the pass lock key relearn got it started and it still running the same guys any ideas!!!? Please idk what to do?