D15B with a P28 ECU, CRX converted to OBD1 via Rywire harness.

The car's still running rich, which is still causing the ECU to throw code 43 and put the car in safe mode... Code 43 basically means that the car's not running right (usually rich) and the O2 sensor is reporting a condition besides stoch. If you look the error up it gives a very generic "Fuel System Malfunction" description.

Some things I've tried, resetting the ECU each time... fuel related things for obvious reasons, coolant related things because I read that if the ECU thinks the engine's cold it'll dump fuel like mad, causing the car to run rich and eventually throw Code 43.

Here are the things I've tried:

Changed O2 sensor for known good OEM one.
Changed plugs for known good ones (NGK-R).
Changed plug wires known good ones.
Changed temperature sensor for known good one.
Changed temperature gauge sending unit (wasn't working, probably unrelated).
Bled the coolant to remove air from system.
Changed FPR for a known good one.
Changed fuel injectors.

The only things I have yet to check or replace are engine grounds, a new thermostat, and a new ECU.

After that I'm out of things to try.

Anyone have any other ideas?

 

do you check to see if all your vacuum hoses are connected and do not have holes

 

thought 43 was for the heated part of the o2 but i might be wrong.

 

Yep - checked the hoses and they're all fine. Everything on the intake mani is as it should be... I even put the charcoal can and the re-circ stuff back in.

Code 43 is a general fuel system error, the O2 sensor errors are single digit CEL codes.

 

next thing could be your fuel filter

 

Replaced the thermostat with a new OEM Honda one.

Hooked up my fuel pressure gauge and tested the fuel pressure. It's dead on with the spec in the manual, so that eliminates fuel filters or pump according to the Honda repair manual.

Swapped ECU out for a different one and it still does it.

I'm just about out of ideas.

 

I'm willing to bet that the problem is in the wire harness conversion.

 

I have this exact same problem and I am stuck too.

I have no conversion harness though as my car is a EUDM Civic VTi (EG with B16A2).

My AF UEGO gauge reads mad rich beyond its scale (10ish:1) and fiddling with the throttle temporarily leans the mixture just to become way rich again. Tried changing the o2-sensor and it was fine for a day or two then CEL code 43 pops up again. Guess the o2-sensor is fubar once again...

We seriously need help before all this fuel foules our rings

 

i had the same problem mine was after about a 45 min drive i replaced the fuel filter and the problem went away

 

The fuel filter is also changed.

However I can't see how a bad fuel filter can cause too much fuel? A bad filter would cause a lean mixture, correct?


Modified by Wafler at 4:17 PM 2/17/2006

 

I don't see any evidence that you're running rich. It's just an assumption you've made.

Check to make sure you have the correct O2 sensor and check it's wiring.

 

Could it be that running a 1.6l ECU on a 1.5l engine is the cause?

 

If you replied to me, suspendedHatch, I have an AEM wideband with a gauge as I stated above. O2-sensor is wired correctly. Still stumped...

 

try another conversion harness...wouldnt be the first rywire harness ive heard about/seen that wasnt done correctly