91 accord code 43

Help! reoccuring check engine light reading code 43. Only comes on when engine is hot. Shut it off and it goes out. Changed 02 sensor 4 times in 3 years. New one very's in lenght of time they work for! Once was told aftermarket 02 sensors dont last in honda's, only original parts. Any ideas as to what would cause this?

Quit replacing 02 sensors. A check engine light doesn't mean a bad o2 sensor. In your case, code 43 indicates a fuel supply system problem. Now it could be a fuel supply system circuit OR fuel supply system problem...not sure which. I'd start checking out:

I'd replace the fuel filter if it has over 60k on it.
Then I'd
1. Check the fuel pressure
2. Check the fuel pressure regulator and all accompanying vaccum hoses for air leaks.
3. Fuel pump ( can you hear any noise from the fuel pump) it might not be getting enough voltage at low rpms. Hotwiring it would solve that specific issue.
3. Vacuum leaks
4. It could also be the main relay or injectors...however being that it isn't consistent I'd probably lean more to the main relay over injectors.


Also there is an an "IMPORTANT" thread titled 'service manuals' at the top of the accord forum. Check in there, and you can download your appropriate service manual, and see what instructions it gives you for diagnosing this problem.


Could you be more specific on what the conditions are when the light comes on (besides a warm engine, does it happen while stopped and idling or when cruising, etc), and how long you turn it off to make it go away (also are you disconnecting the battery in that time or just turning the ignition off?)