full Circling

take off your cat, reset the ecu, and see if that clears it up. then you will know if your gutted cat is the problem or not. even gutted cats cat kill exhaust flow.

also, use a can of something that will get rid of water in your gas tank. iso-heet, water wetter, etc. then you can eliminate another potential problem.

EFb18b

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ^^whatnoobsearchthenGTFO &raquo;</TD></TR><TR><TD CLASS="quote">take off your cat, reset the ecu, and see if that clears it up. then you will know if your gutted cat is the problem or not. even gutted cats cat kill exhaust flow.

also, use a can of something that will get rid of water in your gas tank. iso-heet, water wetter, etc. then you can eliminate another potential problem.</TD></TR></TABLE>

This was going on even before I gutted the cat but I'll give it a shot sometime during the week. As for the water in the gas tank, I threw some iso heat in before I even put the motor in because I knew the car had been sitting for a while. I've been driving the car 45 miles one way to work everyday since march, I would hope that any water that might have been in there is gone by now.

EFb18b

Is it possible that the o2 sensor is in the wrong location? Right now its in the collector just before the cat. Shouldn't it be up closer to the head where its a little hotter?

I noticed when my old tranny had taken a dump and I couldn't get it into 5th gear, that the light didn't come on when I left it in 4th.

full Circling

did you get a code 43 before or after you installed the header?

EFb18b

header has always been there

efnfast1

check the voltage to the map , and try a diff. comp. possible burned diode..

xero_xero

did we ever find a solution to this problem?

grumblemarc

iTrader: (4)

Really? After 5 years? I would hope so!

Rat_Bear

Ive got a friend that has the problem and now I have the problem. I've read alot of stuff. But it looks like these are the things to do.

Code 43 is "fuel supply system."

This code will trip when the ECU and the readings from the o2 sensor don't get along

How to diagnose and fix?

First things first, when was the last time you changed your O2 sensor? Start by replacing that first because most likely, that's the main culprit. Now, you may wonder why doesn't the CEL indicate code 41(heated o2 sensor)? Usually when the o2 sensor is completely dead, that code will trip. Also, even though the o2 sensor is working, the voltage or ground isn't 100% Because of that, it will correlate with code 43.

If replacing the o2 sensor did not help code 43 to disappear, next thing is to replace your fuel filter. A clogged fuel filter will also trip code 43.

Next up, did you install an aftermarket Fuel Pressure Regulator? I have a few friends with 3rd gen Preludes and both of them installed aftermarket FPR's and they too, trip code 43. Him and a lot of people who install aftermarket FPR's mess with the PSI and that will cause code 43 to appear(on a stock ECU mind you). Bring it back to stock PSI to help fight code 43.

Those are the 3 main culprits that will cause code 43 from my experiences. Injectors, spark plugs & wires, most likely anything "fuel' related that isn't working properly will also cause code 43. Fuel delivery has been comprised.

Also other things: Fuel return line. fuel filter. gas cap. Even a clogged cat! This code is the most annoying code ever. PLEASE EVERYONE POST WHAT YOU DID TO SOLVE IT. F%^& code 43!

coreus93

Hi all, i have 94 civic swap b18b with code 43, car start good, choke at 1600rpm, but ! after 10 minutes running check engine pop and idle drop to 600(average). if i turn of, and start, idle going like, up down up down, i dont know what i have to check fisrt, 02 sensor, tps, fuel pump, injector,Fuel pressure regulator. Car come ''hot'' and code 43 pop, maybe, sparkplug seals, or gasket valve cap ? water into sparkplug ? thank for reply !

Rat_Bear

TPs and iac.

91-beaterlude

hey i just got a 91 lude, no 4wheel steer. but i also have this dumb code 43..
any deffinate answers yet? or straight to the changing of the o2 sensor(s)?

my car sat for about 2 years+/- ive cleaned plugs, wires look ok, recently ran a fresh tank of fuel and currently on a premium mix with octane boost + inj cleaner. also thinking of just changing air + fuel filter ( where is fuel filter located? fire wall>?) car seems to smoke alot at times and smells really rich or lean ive been told both. ANY IDEAS??

VTSOHCnon

I just bought (2 weeks ago) 94' GSR 2dr. I drove the car for 3 miles after purchasing it, and the CEL came on. I brought it back to the guy i bought it from and he said it was a bad knock sensor; he said he changed it. I left and drove 26 miles and the CEL came back on, this time with a 43 code...
I noticed that there is an exhaust leak in the collector. So I order a RMF Style Header and it will be installed Friday. I'm hoping that that is the problem; how likely that I'm right?

Also when I'm just pulling out of a parking space and I hit 2K RPMs at part throttle, in any gear, the car starts stumbling, huffing and puffing. If I floor it, it will come out of it. But the CEL won't come on until I've reached the highway; which is about 3 miles down the road.

wmj011

Where is the aft o2 sensor?

I had the car (1995 Accord LX) on the lift today and could not find it. I stood under the car with a clear view from the engine, tailpipe, catalytic converter, something else, and then the muffler.

What do I have to remove to get to the aft o2 sensor?

I replaced the forward o2 sensor, the one on the exhaust manifold, recently, so I know what they look like.

BTW, this is a pretty good thread. Good info on how to deal with the dreaded code 43.

holmesnmanny

You only have one.

wmj011

I recently replaced my o2 sensor with a Denso part. I went to the Denso web site to make sure I got the right part #.

Was that a mistake?

Should I have used the genuine Honda part?

wmj011

My mistake. I noticed today that the o2 sensor plug was loose. I didn't push the 4 pin connectors together tight enough when I installed it.

This time I pushed them together until the 2 connectors snapped into place.

Problem solved. No more bogging down; no more code 41; no more code 43.

wmj011

Thanks. You are right. I was using the Haynes manual. It is not as clear as I would like it to be about the different Accord versions.

On the parts fiche for my car, it shows an o2 sensor in the exhaust diagram, but it does not show the part in the list. I guess they copy and paste diagrams a lot.

The LX V6 has an o2 sensor in the exhaust. I guess that was the version the Haynes manual was using.

Tummy

i had the same problem with o2 sensor..
because my sensor in the header was in the bottom, not in the top next to the engines output..

i put a 3 or 4 wired lambda with a heat segment..
my problem was the sensor didn't get hot enough because it was in the bottom

UndisputedH22a

My jdm Itr swap in in my ek is doing the same thing and it is doing the USNR thing and I've been trying to work this out so I'm gonna look into some of these answers n see if I can solve it

sivicman

I have a '00 Si w/Vortech S/C, and RC 440 injectors, and Walbro pump. I have Hondata S100 w/boost with stock ignition. Car was modified in 2003 and has been left alone since. The car is now giving off a Code 43 and goes into limp mode. After reading most of the posts I replaced fuel filter and gas cap. The O2 sensor has been bypassed by the tuner. The car idles fine and runs fine until hot and you shut it off then restart it, then the CEL light comes on and you can't floor it because it boggs down. This has happened once before last year and now it's all the time especially when the A/C is on. HELP!