Q: Service engine light is on

asked by on

I'm trying to figure out if i need to replace the catalytic converter or is it the oxygen sensor. Should i replace the oxygen sensor first and if so how do i know which one to replace because my car has two oxygen sensors????

My car has 150000 miles.
My car has an automatic transmission.

Hi There, Generally when the check engine light is on, it will register a code in the computer indicating which oxygen sensor is bad. i would suggest starting with replacing oxygen sensors first as this is much more common to fail than a catalytic converter and is much less expensive to repair. I would recommend having a professional from YourMechanic come to your location to diagnose using a scanning tool which should more specifically narrow down what the cause for the check engine light might be.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Service engine light is on

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: Trunk won't open on my car

Go into your control setup in the instrument panel, under user controls, and make sure the trunk did not get turned off in the setup. If it did, then turn all of it back on and the trunk should open....

Q: hello

You will need to check the trunk lid sensor to see if it is loose or out of position and not registering the door position correctly. If you need assistance then contact a mechanic like one from YourMechanic to diagnose...

Q: Why would my radio and speedometer stop working on my 2004 Chevrolet Malibu

Hello. If both of these issues started occurring at the same time it is because there is an issue with voltage in the system. Most of the time on this vehicle it is caused by either a low battery, a...

Related articles

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...
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.