car = 93 accord ex stock 125,000 miles. 2.2 L4 sohc pfi 16v F22A6 Ilive in falgstaff Az. elevation 7,000 feet very little O'2 in the air. the car had no trouble reaching 6,500 rpm. at 5,000 ft. now will not go past 5,300 rpm? I could use any help I can get.