1992 Honda Accord Check Engine Light

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1992 Honda Accord 4 cyl Front Wheel Drive Automatic 205K miles

I have a 1992 Honda Accord EX with 205,000 miles on it. Recently, during an extended highway trip, the check engine light came on with no real degradations in engine performance. The flashing code is 43 which points to a fuel system problem. The light will extinguish for awhile if the car is turned off and then restarted. With a cold engine, it takes about 15 minutes of driving for it to come on. If the engine is warm, it only takes a few minutes for it to come back on. Also, sometimes after starting it cold, there is the slightest hint of a fuel smell inside the car. I have checked for fuel leaks, vacuum leaks, and changed the vapor canister to no avail. The only noticeable change in performance is the idle speed seems to be a bit lower when the light is on. Is there something else in the fuel system I am missing? Does the O2 sensor have an input into this trouble code? Thank you,
Jim