Important new information. The new intake.
Combined with hot weather that may be your problem. If you are feeding the engine hot under hood air that could explain your problem. You need to have the intake inlet where it gets cold air or you need to create a hot air dam.
You may find more with a search on such topics as "hot air dam", "hot weather power loss", " or "cold air intake". One of the veterans here made his hot air dam from an old plastic trash can lid.
