sup guys, been a while since iv been on here but figured id post since my accord has a problem after over a year.

the first code i got was for a o2 sensor " downstream " about 5 months ago. car ran fine no problems other then the light turning on and off every couple 100 some miles.

the light was off for about 3 weeks and came back on, and now i am getting codes for the downstream and upstream o2 sensor.

would that be implying the cat is bad? showing both o2 sensors are bad? or can it be that both o2 sensors are just bad and should be replaced.

1998 honda accord f23a4 ULEV....

and on the same note.. any brand in particular for the o2 sensors? and do they gotta be specific to the ulev or can i just get standard o2 sensors for a f23 motor.. cause the diff between f23a1 and f23a4 is the ultra low emission vehicle... which im pretty sure the cat and o2 sensors are different and cost more $$

thanks guys for any input

 

Please provide the actual code numbers for your vehicle. Your description could apply to several faults that have different codes. Code is form Pnnnn.

good luck

 

i can check the codes again cause i dont remember the #'s but they were the same code but 1 number off. basically bank 1 and bank 2 flow efficency

 

None of the O2-sensor codes are about "flow efficiency". There's high-voltage, low-voltage, sluggish, etc. And many of the different codes are 1 number away from each other.

 

p0420 and p0430. first came the downstream code and a few months later came the upstream code. below threshold somethin somethin -.- cat itself maybe 2 yrs old since i last replaced with a oem 1. car ran fine with the downstream being bad. since the upstream code the car seems to be off a/f wise at higher rpms, fuel smell when toying around above 4500 rpms

 

P0420 is catalytic converter efficiency below threshold. It is not an O2 or Air/Fuel sensor fault. The cause for this code can be a failed converter, exhaust leak, fuel delivery problem, etc.

P0430 is not listed as a fault for 1998 Accord. It is used for V6 engines in later models and is similar to P0420 "front bank catalyst efficiency below threshold".

Did you extract these codes recently? No other codes?

good luck

 

yep just pulled again yesterday. and p0430 was the original code from months ago i pulled for the 4cyl 98 accord.

description is the same exact as p0420 except 30 is downstream and 20 is upstream. which made me think o2 sensors. there is 0 exhaust leak and fuel delivery i gotta check

 

P0420 is determined by the downstream O2 sensor, however does not mean the sensor is faulty.

P0430 is not a listed code for 98 Accords, ULEV or otherwise. Not sure what to make of that, but could indicate faulty ECM.

If you have access to a obd2 scanner, suggest resetting ECM/PCM and see what codes return after driving.

good luck

 

ill reset it tonight and start driving tmrw since honda day over and i can park my crx for a few days to rest. will let u know in 150 miles what codes return