Just like the title says I'm getting code 43 on the 92 civic d15b/z6 p28 ecu. I can drive the car all day long with out seeing the code for days even it's not until I got WOT over 4-4500rpm then the code will appear until the car is shut off. The code is stored but cel goes off when started again. I've noticed sputtering at low rpm as well anybody seen anything close to this?

 

Fuel filter, fuel pressure regulator, primary O2 sensor. Test and replace, in that order, all three of the above as necessary.