Hey Everyone:

I have a Accord that has 180,000 m on it and I've been getting the two P0430 and P0420 codes on it. 2 mechanics I took it to fell that that cat's the problem but I just want to get some other opinions before I invest in a new cat.

Thanks.

 

Usually the P0430 code is either the cat, or rear sensor. Not sure what the P0420 code is. What year is the car?

 

P0420 is for the front bank catalytic converter, and P0430 is for the rear bank converter. Both are that the catalyst is below threshold. I'm guessing this is a V6 accord?

Are there any other codes, or previous work done on the car?

Is this constantly happening over several tanks of gasoline, or did the check engine light turn on after say filling up the gas, or any work done on the car?

 

Thanks PAhonda. I wasn't sure if the P0420 was the front O2 sensor or not. Ive never had that code come up. The P0430 code yes. And everyone suggested replacing the O2 sensor, but instead I replaced the cat and used my old O2 sensor. It's been fine for over a year now without that code. I guess my old (non-stock) cat was bad.

 

1) Yes it is V6 Accord

2) No there aren't any other codes

3) Yes the code is constantly on. I've noticed my fuel economy is very poor.

 

The poor fuel economy is related to the P0420, as that's the upstream sensor (or fuel mix sensor).

 

I wouldn't make the call on the upstream O2 sensor based on the current information. The next step would be to monitor the fuel trims to determine how the engine computer is adjusting the fuel to manage emissions.

 

P0420 and P0430 are related to the separate primary catalytic converters. The 7th gen and 8th Accord V6 has 3 converters, the codes relate to the primary converters (bank 1 and bank 2) shown in the attached pic.

Each primary convertor has separate up stream air/fuel ratio sensor and downstream oxygen sensors; respectively. So, it is unlikely to be due to one sensor or the sensors. On these generation Hondas, it will most likely be due to bad cat converters.

Although not normal for both primary converters to be bad, it is possible. Does the car burn oil? If the car burns oil, etc., it may have caused both primary converters to become bad.

 

The car doesn't burn oil that I know of. It is pretty old, however.

 

Can you provide us more information about your car? The year, transmission, LX,DX,EX trim?