I have a 1993 Honda Accord SE with 130000 miles on it. It recently started having the check engine light come on when you drive at a steady speed for about one mile and above 30MPH. It set an engine code of 43 and when you turn the engine off the light does not return until you repeat the above.
So far I have replaced the fuel pump and filter, you have to turn the ignition on wait several minutes before it will start.

Never heard of this before. I'd focus on the oxygen sensor, where the CEL may be coming on when it comes out of "open loop" mode. In my experience, it will throw a code and store it in memory. The link below may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html#post223376