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: Brake light switch continuously fails

Hello. You may want to check the connections at the terminal as it is not uncommon for these to get very hot and melt the plastic inside and corrode. This may also be a rusty ground which can also cause...

Q: Check engine light p2068

It doesn't like you have a fuel sensor problem. The codeyou're having could be due to an issue possibly with a wire connection or just a bad sensor. You will find the sensor on the right side of the fuel...

Q: Rear tires on passenger side locked up

I would not drive the vehicle until it is looked at, as it is possible for the fault to cause an unsafe driving condition. When a brake locks up without any reason, it is most likely caused by a failure...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...