Operas,opener,or sparse
appeal
apiece
spruce, opaque
Apache, apathy, appeal, append, apples and aprons are 6 letter words that begin with the letters AP.
open
The second letter is P. It comes right after the i, and before the a.
Some six letter words with p as the second letter are opener, operas, sparse, and apiece.
limp
happy
The word "spout" fits your criteria, with the second letter being 'p' and the fourth letter being 'u'. If you have specific contexts or additional criteria in mind, feel free to share!
bishop
P is for phony.