Hi Folks,
For the longest time I have had a problem when taking my Honda wagon on the highway. The check engine light comes on after only a few short minutes above 70 km/hr - 40mi/hr. It does not come on around town and the engine runs fine. The OBD code is 43 which is "fuel system problem." I have cleaned, tested and or replaced all of the obvious fuel system components and even removed the ports and cleaned the EGR manifold. Lately if I try to drive above city speeds it starts to stutter and buck slightly and will not accelerate no matter how much I push on the gas pedal. After a short time the check engine light comes on and everything clears itself and the engine power and rpm return and all is normal again even at highway speeds. Any ideas??
Regards,
Rickweath
Victoria BC

 

Normally the first thing to think of when this code comes up is to replace would be the oxygen sensor with a Denso unit.

 

Hi, much thanks for the info. I have already replaced the sensor around 6 months ago but I am not sure it was the Denso brand. I will get it checked again. I am also wondering if it might be a sensor in the mass air sensor unit. About the only other thing I havent looked at is the fuel return valve sensor.
rick

 

This is a really pesky code. I would probably pick up another ecu from the junkyard and if that doesn't fix it, take it back and swap it out for another set of injectors from a 90 - 93 accord.

You can also check for an exhaust leak by seafoaming on a cold start when the engine rpm is automatically up at 1500 rpms, look for white smoke coming out anywhere from the exhaust manifold to the oxygen sensor.

 

Yep, you are right. 43 code is very ambiguous and can mean many things. Okay, I will check O2 sensor, then look at the ECU. The injectors seem to be fine because they work at all times at any speed. The idle is smooth and high speed driving is really good/problem free as long as the check engine light comes on. Fuel pressure is normal so no problem with pump. Sure could be the ECU. Soon I am going to give up on this whole problem and take it to my favorite mechanic. At least he will have some proper diagnostic tools to check on O2 voltage levels etc. Thanks again for your advice and perspective.
Rick