what cause a obd 1 error code 43 in a 91 accord ex on 1991 Honda Accord

put in a Bosch 02 sensor, new plugs,wires, 3 weeks ago then the check engine light comes on when I go over 55 miles an hour on the freeway, I was told need new fuel pump

Asked by for the 1991 Honda Accord
Sounds like EGR valve. Its not cheap but easy to replace. Take it out and clean it. Thats worth a try and free !