Dealer flashed PCM and TCM. Trans will not downshift on passing. Feels like trans is starting off in 4th gear, not first gear. The manual gear, + - , works sometimes. Any suggestions???

 

Still starts off in 4th. No codes showing. What does flashing the TCM do?

 

Sounds like you're in limp mode or something is off with your TCM. Why did the dealer flash your computers for a replacement engine? At most MAYBE the TCM might need an adaptive reset (I'd have to check). Take it back to them, make them figure it out since they screwed it up.