maki

I'm presently experiencing a CEL problem with my 94 Integra RS (177,000km / 110,000miles). But, the car seems to run fine!!! The code is 43 which indicates a problem in the fuel supply system. I also have reset the ECU several times during the past months but the CEL reappears every time soon after. I've changed the following parts during regular maintenance: spark plugs, fuel filter, and pcv valve.

How do I know if the oxygen sensor needs replacement?
How do I know if the ignition cables need replacement?
Would the problem be related to the distributor cap and rotor?

Could anyone out there steer me in the right direction...

TheOtherDave™

I'm used to dealing with OBD-2 codes, but I'm a little rusty on what's covered for OBD-1. h:

• A faulty O2 sensor would (I think) log an entirely different code.
Also, fuel mileage would suffer.

• I'd only suspect the ignition wires, distributor and rotor if you had hesitation or stalling issues. :dunno:

• If the code is related to teh fuel system, then I'd check line pressure & injectors first. Use our search engine to pull up the instructions on how to perform each test.

Since the car seems to perform well, I doubt the ignition system is an issue.
Has your gas mileage gone down recently?
Any problems starting?

JimBlake

43 is kind of a catch-all code. If the O2 sensor, MAP sensor, TPS, or whatever is disconnected or totally screwed up, they have their own codes. But if they all together don't add up to an operating condition that makes sense to the ECU, it throws code 43.

Say for example your fuel pressure is wrong. The ECU would have to increase or decrease injector duration in order to keep your O2 sensor happy. Then it would throw code 43 because the ECU really has no way of knowing what your fuel pressure is. So there's lots of troubleshooting for this code, it can be many things.

cartuner

You said the car runs fine, means this is a O2 problem. The O2 is only being used in close loop. This will throw the code only in closed loop. So it will throw the code during cruising at a steady speed or at idle. You can hook up a multimeter to measure the voltage of the O2. Red to white wire of o2 and black to any ground. When idling the O2 should sweep from .2 volts to .8 volts and repeating this over and over. Check this also at pinout D14 of ecu too. If voltage does not move up and down you have a bad o2. Hope this helps.

maki

From the literature, code 43 is described as the following: "fuel supply system defective or malfunctioning fuel supply system". What kind of symptom should I be paying attention to when I drive the car? For instance, I reset the ECU and drove the car for 3 minutes in my residential area (stops and lights), 20 minutes of highway (cruising speed) and again ended with 3 minutes in a residential area (stops and lights). The CEL did not come on at all. But, it reappeared 2 hours later, on the highway, on my return trip back home. At other times, it will appear in my two minutes of driving the car. It all seems to happen at random!!!

The following has puzzled me for months !!!!!! Many, many times, I have tried to pull over as soon the CEL light comes on (2 minutes drive) to turn off the engine and immediately start again. Then, I will take the highway and continue for 30 minutes with the ligt NEVER coming back on again for the day? The same scenario would occur the next day with a cold engine. How is this phenomenon explained ????? (O2 sensor: closed loop theory)

I will check the voltage from the O2 sensor at idle with a multi-meter...
How do I locate pinout D14 of ecu?
My gas mileage has not gone down recently.
I haven't had any problems starting the car.
How do I check fuel line pressure & injectors?

Thanks guys,
The feedback is excellant!

maki

Somebody help me!

maki

Can someone please help me.