Tonight I figured it a good idea to degrease/wash my engine bay, due to a nasty oil spill when the oil fill cap came off. After I was finished and on my way home from the car wash, my car started throwing ECU Code 43 - Fuel Supply System. The car showed no difference in how it ran, and the only work I’ve done to it recently was a valve lash job earlier this morning. I like to consider myself pretty mechanically inclined when it comes to Integras, but I’m clueless as to what is causing this code. I have a full cold air system that runs down into the wheel well under where the stock air box use to be, thinking water may have gotten in the intake, but I was cautious about water around that area…plus as I had said before, the car is running fine. Any opinions would be greatly appreciated.
You probaly got water on the " o2 sensor "
i highly doubt you got a substantial amount of water inside of your intake [ you would’ve noticed it then ] and the code has no relevance to that sort of problem either
the o2 sensor runs along the tranny [ right below the distributor ] and into the downpipe / lower section of your header
you might be able to take it out and let it dry… [ unless it was the chemicals that got on it ]
in the case that you buy a new one, i wouldn’t go to autozone and get the universal bosch one go ahead and go to honda for the factory denso o2
the boschs seem to be have a short life
+1
i ruined my o2 sensor when i cleaned up my intake mani with carb cleaner while i had the TB off, i figured it would and i had a new one on hand, but it shows how sensitive they are. and remember your not supossed to even toch the actuall sensore.
My first thought would have been the o2 sensor, but wouldn’t that cause a code other than 43 - Fuel Supply System? I haven’t had a chance to run my car since last night, I was hoping that my letting it sit that the water would evaporate and possibly solve this issue. I’ll try the o2 theory, I have a spare on hand. If this doesn’t work I’ll post again. Thanks for the help everyone. 
Sounds like you got some part of the fuel electronics wet. Just let it dry for a bit. I’ve seen shit happen to people who do this shit without proper cover over everything.
I just take mineral spirits with a rag and whipe it clean. I can at least see where it’s all going
Code 43 is a code for the fuel supply system, but it 99.9% of the time is a code thrown by a bad O2 sensor. I also ruined one of my O2’s by getting it wet washing my engine, so thats probably what happened to you as well.
Tip, do NOT buy a bosch O2, they SUCK for our cars, dont know why, but i myself went though a few of them, and most others I read about also had them go bad in a few weeks.
DENSO is the brand of O2 that you want, if you cant find it locally, get it online, its way worth it, runs about 40 bucks.
This may not help you at all, but a car wash once ruined my ignition coil, I know you’re getting a code 43 and no symptoms like the bucking above 3k that I got. I never got any code.
My intake doesnt run under the fender but I have part of the fenderwell cut out and once in a great while through big puddles I’ll throw CEL and the car will go into limp mode, I never get a chance to get the code because its cleared as soon as I shut the ignition off, and all is fine.
Did you reset the Ecu yet?
my code 43 was o2 sensore. its almost always the 02 sensore
yeah bosch o2 sensors suck balls. I’m selling my 90 DA and throwing in the bosch one to sell it. 4 months ago I bought a brand new acura o2 1-wire o2 sensor and that’s what i run. It was the big $$$. I’ll sell it to you, shoot me an offer.
My other integra is getting an OBD1 o2 so this one I need to sell off.
NGK O2 sensors are affordable and top quality.
http://ngk.com.au/part_index.htm?http://ngk.com.au/PartFinder/sensors.php
that site didn’t work. It’s also not even a USA website.
I let the car sit for more than 24 hours, and all seems fine. The only issue I noticed was it bogged in 1st gear upon take-off, but that cleared up instantly after getting on the throttle. Looks like I’ll be more careful about covering things next time around. Thanks 
Mine did the same thing today when warming it up. It threw a code 43 but had no change at all. I did not get anything wet but by the looks of this thread, I am getting a new O2 sensor. www.sparkplugs.com has some great NGK and Denso ones for cheap.
usually that happens when the TPS sensor gets wet too, just blow dry all the plugs you think got wet, it should solve your problem, then take your neg. battery terminal off and wait 30 sec, then put it back on, that resets the ecu