the book says fuel but i dont know what that means.......please help

 

What car/engine/ECU/mods?

Typically a Code 43 is set when the Long Term Fuel Trim has reached its limit of either +/-20%. This value gets set from O2 sensor feedback.

Does that mean your O2 sensor is bad - No, well, not until you reveal your setup.

You could be running that rich/lean to set the code off; your O2 could be duffed; the wiring for the O2 could be duffed as well.

 

its a 95 civic ex with an h22.........everything is completely stock

 

so is it just the O2 sensor?

 

Lets say your fuel injectors are a little more than clogged. This would mean that for the ECU to achieve the same a/f ratio, it has to keep the fuel injector open for a longer amount of time. The ECU 'sees' that it has to keep the injectors open for a longer period of time to get the O2 to do what its expects it to do (swing) - it does this via the Long Term/Short Term Fuel Trim.

So you see, in the above scenario, was the O2 the culprit? No, it sure wasn't - so I'm a little hesitant to say "replace your O2" when it could be anything that is restricting fuel flow/air flow and making the ECU adjust out of its operating range.

You say you're bone stock - how many miles are on the O2 sensor? Is it OEM - or Bosch garbage?

What about the rest of the engine maintenance - plugs/cap/rotor/wires and all that jazz?