So I have an 03 Accord ex coupe 3.0l v6 and I have a p0430 I replaced both air ratio Sensors and I replaced the bank 2 catalytic converter but code is still there scanner tool shows the 02s are fine what else could it be? Some say they had to get a software update I'm tired off throwing 100s at the code for it to come back please help!!!!!!

 

What is the secondary O2 sensor voltage after its warmed up? It should NOT match the primary, but should remain at about .7 volts.

 

The 02 Sensors are fine I'm not near a scanner at the moment but if they were faulty it would be kicking a p0420 with obd2 430 is for the cat being below efficiency even though it's new

 

Get a 90° o2 sensor relocator it pulls the sensor directly out of the flow of exhaust tricking the ecu into thinking nothing is wrong. Then your check engine light will go away. I've been running one for a year no issues. PLM sells it for $20

Also I don't know how long the code has been present but my car when I purchased it had an evap code for 3 yeara prior. Evaps are a pita to diagnose. So needless to say I replaced the whole evap system and it still was there. Come to find out the code was there for so long it was "burned" into the ecu and wouldn't clear. So I changed the ecu and no more code.

 

Yea It was on mines for a year bought it like that and I replaced stuff still on taking it to honda to see if all I need is a ecu software update but I don't want to trick it. I want to make sure it's fixed because my gas milage isn't the greatest either I know it's a v6 but a half of tank lasts me a day and I don't drive far at all

 

I'm aware you replaced the o2 sensors as you stated in your first post. What I'm getting at is you need to actually see the signal of the secondary o2 sensors. This will tell you if the catalyst is doing its job or not.
P420 and p430 are catalyst efficiency faults. The ecu only uses the secondary o2 sensors to verify catalyst operation and have nothing to do with fuel adaptions.
Secondary o2 sensors should flatline with a good catalyst. The primaries are the ones that will oscillate.
Also check for exhaust leaks before the cats. An exhaust leak will actually suck in a small amount of oxygen and can make the ecu think your running lean and command more fuel to compensate for this false lean condition.
Are there any other codes along with your p0430?

 

No just p0430 took it to honda today and the scanner said that the cat needs to be replaced could it be a bad cat put in by Midas honda said the car didn't look new but I watched Midas put it in

 

The most likely/common cause of a p0420/p0430 fault is a failing catalytic converter.
Being aftermarket (Midas), there's a good chance its probably not doing its job, hence the constant P0430 fault code.
The dealer technician should know what to look for as far as sensor voltages and patterns.

 

Readings I'm getting
02S12 OSCILATING
02S22 OSCILATTING
02S11(MA)-.01
02S21(MA)-.031

 

Ideally you would like to graph all 4 sensor signals to actually watch the voltage patterns.
But from what you said, sounds like a non working cat.