P0236 FORD - power stroke 7.3 96 model

Question

In second gear when engine is warm, you can press on gas and it is like it stalls after 2000 rpm and stays stalled. When you hit 3rd gear it runs good ( TURBO SPOOLS UP AND IT TAKES OFF) In winter time , I have noticed that when you first start out it spools up and runs like like I think it should all the time ( IN SECOND GEAR) UNTIL IT GETS WARM. Then it doggs down in second gear when you get on the gas. Runs good and turbo spools up en every gear except
2 nd gear. Read this code last time i got check engine light, P0236