'always' needs to be removed - the sentence is confusing with it.
"To pass the final examination, Peter has to make every effort to do his best this year."
Not necessary, but personally I would make a small change at the beginning of the sentence.
"In order to pass the final examination, Peter has to make every effort to do his best this year" or
"So he can pass the final examination, Peter has to make every effort to do his best this year"
This is just a suggestion, it's not necessary.