Q: Q: Bad O2 sensor

asked by on

I am getting code P0420. I think it is the O2 sensor, bank 1.

Hello, code P0420 represents right main catalyst deterioration. There can be a few things that need to be checked before replacing parts. The intake system needs to be inspected for vacuum leaks and unmetered air leaks. The exhaust system should be checked for leaks, from the exhaust manifolds all the way to the oxygen sensor after the catalytic converter. A scanner should be connected and the oxygen sensor. After, the car should be monitored for voltage activity, and test to see if it can be driven rich and lean. The mostly likely failed part is the catalytic converter,but some people believe in trying an oxygen sensor first. I would have a mechanic inspect your vehicle and let you know if you need a oxygen sensor or catalytic converter replacement.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Q: Bad O2 sensor

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car kicks out to the right while driving over small bumps at high speeds

The axle could be the issue. However, the reason the axle is jumping in and out is more likely due to a worn bushing or control arm. The control arms hold the tires to the ground. With your vehicle, you...

Q: The car idles up and down. Replaced throttle body temperature sensor, mass airflow sensor, and oxygen sensor.

Hello. If you have taken all those steps and the idle is still not at the correct speed, then the next thing I would look at is the idle air control valve. The idle air control valve is the component...

Q: The ESP warning light is on my car and it won't start, it a 2016 Hyndai elantra, I only had it for like 6 mths.

Claimed by Jeff Engstrom

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...