Q: I'm getting a po420 code the car is losing power. What are the odds it's the cheaper rear cat?

asked by on

I'm getting a po420 code the car is losing power. I've changed the downstream sensor no luck. What are the odds it's the cheaper rear catalytic converter? There are no sensors after the rear cat. I'm hoping there's a chance it could still be that one. The front one is welded to the manifold and a lot more money to replace.

My car has 103000 miles.
My car has an automatic transmission.

Hi Jason. When the oxygen sensors have readings that are similar to each other, it is an indication that the catalytic converter is not working as intended. If the voltage of the downstream oxygen sensor decreases, and begins to fluctuate like the upstream oxygen sensor, it means that the oxygen levels are too high and the Powertrain Control Module (PCM) will store the P0420 trouble code. It might be a good idea for you to read this article on the P0420 OBD-II code, as it will provide you with several ideas as to the possible sources and repair solutions to consider.

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. I'm getting a po420 code the car is losing power. What are the odds it's the cheaper rear cat?

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: Coolant leak and white smoke.

The engine has a blown head gasket and is passing coolant through the engine to the tailpipe. You are seeing the steam coming from the exhaust. The engine being overheated would have to be diagnosed as to why it is...

Q: Cruze 2014 LT motor oil plug is a Left Handle thread ?

Hey Carlos. The oil pan bolt is made out of aluminum for some reason and is a standard right-direction thread, however, it's very small and delicate - so it can be hard to remove. You should see a directional arrow,...

Q: Q: Hood not opening

Hi. You are fortunate that the latch is accessible. You can get under the front of your car and look up just behind the bumper. You will see the bottom of the hood latch, and the operating cable going into...

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.