Q: Q: I have the P0420 code

asked by on

My check engine light is on and I have the P0420 code

My car has 240240 miles.
My car has an automatic transmission.

Hi there, thanks for writing in. Code P0420 has to do with the catalytic converter in your vehicle. The code will need to be diagnosed by checking the vehicle for exhaust leaks, O2 sensor problems, or the wiring to the sensor damaged. If all these check out then the catalyst my need to be replaced. The most common failure for this code is the O2 sensor not working correctly and needing replacement. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

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: I have the P0420 code

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: Started my 2009 cobalt, smelled gas looked under car and gas was pouring out, replaced pump last October. Help!!

If your vehicle is leaking fuel, it can be from a few different places. First, one of the fuel hoses could be leaking. These hoses are made of rubber and can become brittle and crack over time. Second, the metal...

Q: Can putting a EverStart Marine Battery, Group 24MS - 1000 CA in my van damage it? If so, how?

The battery you installed is a 12 volt battery and although the cranking amps rating of the battery you have applies to a higher temperature (marine environments are typically relatively warm environments) at 1,000 MCA (marine cranking amps), that is...

Q: My tire is locking up.

Hi. The most common problem with a wheel locking up can be related to front brake calipers that are loose or binding the wheel. The other common problem is the front hub bearing is also binding the wheel. If any...

Related articles

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.