Q: CE Light came on , got it checked and it said PO420. Couple of day later went off and has not come back on. 2011 Jeep Compass

asked by on

My light came on and then went off and stayed off . Is my converter going bad or is it just a sensor ?

My car has 90000 miles.
My car has an automatic transmission.

Hi there - yes, it is possible the catalytic converter has lost it’s ability to burn residual fuel. This could be due to an engine condition that has clogged the catalyst, or a failing oxygen sensor that is not adequately monitoring exhaust gases, and feeding bad data to engine management. The result is the same, inadequate catalytic converter functionality. I would recommend a Check Engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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. CE Light came on , got it checked and it said PO420. Couple of day later went off and has not come back on. 2011 Jeep Compass

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: I have gray smoke coming out of my tailpipe but it's not heavy smoke and my car check engine light is orange​ my car shut off

You did not mention why the radiator was replaced but I think your engine was overheated causing the head gasket to go bad. This would cause the white smoke out of the tail pipe and an engine misfire and overheating...

Q: Transmision has black oil, had Line a grinding noise and Line a whistle

If the check engine light is on, there will be stored trouble codes and those will provide clues to the mechanic as to what is going on. Transmission oil color is not always dispositive of a fault but if the...

Q: Catalytic Converter Replacement - 2001 Lexus IS300.

Hi there. Before you decide to have the catalytic converter replaced in your vehicle, consider performing the following checks: Check the following: A damaged or failed oxygen sensor The oxygen sensor wiring damaged or connected improperly The engine coolant...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
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...