Q: 2006 Volvo S40 - Engine cut out twice last week - This week check engine light w/ P0420 code reading.

asked by on

Two weeks ago I got a check engine light that keeps turning on and then turning off. Last week, my car cut off twice in two days when I was first parked, then backed up, then turned off when I went to drive forward. It was shaky both times immediately preceding cutting off. When it turns off all lights on the dashboard light up. My friend read my CEL today as it turned on again for a read and it says P0420 and P0420 FD.

My car has 160000 miles.
My car has an automatic transmission.

Hi there. 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. This is typically caused by one or both O2 sensors being damaged or the electrical harness that connects to the sensors is faulty. It would be a good idea to have a professional mechanic come to your location to complete an inspection, so they can pinpoint the exact source of this issue and determine what part repairs are needed to resolve this issue.

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. 2006 Volvo S40 - Engine cut out twice last week - This week check engine light w/ P0420 code reading.

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: No compression in engine

Unfortunately there are a few reasons as to why your Volvo’s engine has no compression. The most common reason I have experienced would be when the timing belt fails. When this belt fails, the starter will crank the engine over,...

Q: Q: Having problems with the power steering.

You may have a bad power steering hose. If you are losing fluid, you will see it leaking somewhere under the car or you may see a wet hose under the hood. Sometimes when the hoses get old they will...

Q: Engine idles rough and jumps between 500 and 1200RPM when shift from Drive to Reverse; Check engine light on

You may have a couple of separate issues: The flashing Check Engine Light under heavy load is most likely an ignition system misfire. This could be something like a coil pack or worn spark plugs. These engines are...

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...
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...
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.