P0420 Nissan altima ( S1 or S2 fail)?

Question

Computer shows P0420 Nissan altima code
Most likly Sensor 1 or Sensor 2 is sending wrong reading - who has experience with it?
also my car starts to burn 11.5L /100 km before was 9 L/km
Which S1 or S2 sensor regulate gas consumption?
Thank You in advance

Answer 1

Hi there,

Most often if it's a bad sensor causing the catalytic converter code, it's sensor 2. It's been my experience that in most cases the converter is the problem and not the sensor.

The front and rear O2 sensors work together to report info to the computer that affects the fuel mileage as well as the mass air flow. These are all contributors to the air fuel mixture that the computer is making. I suspect since you have the converter code, it's quite possible the converter is causing most of these issues.

Also, if the engine is out of time, hasn't been tuned in a while or even has a dirty air filter you are going to see a loss of fuel economy.