Hi, I was hoping you guys could help me with a couple issues I'm having with a 91 Accord EX (F22A4, 259K).

If I go WOT 0-55mph, the check engine light will come on. When I jumped the blue connector, it spit out code 1 O2A - Oxygen sensor #1. I tested the O2 sensor by having a spirited drive, then pulled the car up on ramps. I recruited a buddy to operate the throttle while I crawled under the car and hooked up a multimeter to O2 sensor. We found that it was rather lazy (after going WOT, it would raise to over 0.6V after a few seconds of WOT, and fall down to under 0.4V after a few seconds after the throttle was quickly released. What is the likelihood that the lazy O2 sensor is causing the CEL to come on at WOT? The service manual says that this could be also caused by a bad fuel supply.

Also, the 43 Fuel supply system code came on once when I was driving it. I'm trying to figure it out if these two codes could be related. A new O2 sensor is rather expensive so I'd rather not replace it if I don't have to.

Also, whenever i unscrew the gas cap (even if the tank is full, 3/4 full, etc.), i hear a big 5 seconds long whoosh which makes me think the pressure inside the tank isn't being equalized properly. could that be related?

Thanks!

 

ummmm, when my egr failed I got these 2 codes and coupled with that an irritating idle fluxuation. It took me a while to find out the egr failed due to testing everything.

check it out and see.

gl

 

the engine idles and runs perfectly, tho i will test the EGR when i get home tonight just in case.

 

Ive got code 43 (Fuel Supply System) twice now due to failed oxygen sensors.
Buy the Denso sensor...they're about $70 and well worth it over the $55 Bosch crap (my Bosch didn't last long at all untill it kicked a code again and died)

https://honda-tech.com/forums/showpo...0&postcount=15

 

yea, i found the denso for $41 on amazon and thats what i plan on buying if need be, but i just want to rule out any other possibilities before buying it as this car is on a very tight budget and i don't want to buy unnecessary parts

 

The Haynes Manual contains the full test procedure that I used to diagnose the failed Oxygen Sensors on my '92 Accord and discussed in the link I included above. It might be functioning as a sensor ok after warm-up, but kicking the code due to a failed heater circuit. Check the heater circuit and that may steer you either towards or away from the Oxygen Sensor (depending on whether its working or not).

Good luck!

 

https://honda-tech.com/forums/hybrid-engine-swaps-18/%5Bfaq%5D-%22my-vtec-doesnt-work%22-1812135/

halfway down

 

thanks guys, I followed the steps, confirmed it was the o2 sensor and got a new denso o2 sensor and the CEL hasn't come back on.