my 05 Odyssey EX check engine light comes on. The ODB read P0420, O2 sensor Bank 1, and P0430, O2 sensor Bank 2. I want to replace them myself but the van has 4 O2 sensors. I wouldn't know with two to buy. Also, does anyone know the location for the sensors?
P0420 and P0430 indicates that the reading from the second O2 sensor is close in value to the reading of the first O2 sensor on each bank. This generally means that the Catalytic converters are Not reducing your emissions enough. The first O2 sensor reads the exhaust as it enters the catalytic converter and the second O2 sensor reads the exhaust after it comes out of the catalytic converter. The ECU compares the readings and if the emissions level do not drop enough in value you get the P0420 and /or the P0430 code. One code for the front bank of cylinders and the other code is for the rear bank of cylinders. Each bank has its own Catalytic connverter.
The sensors are most likely working. When they fail they give a different codes.