Q: Check engine, traction off lights are showing

asked by on

I purchased my car used, and the check engine and traction off lights are on. I checked on the code scanner, it showed: knock sensor. After fixing that, then O2 sensor codes starting show. What else do I need to fix?

The Check Engine Light is likely still on due to the oxygen sensor faults. The unfortunate thing is that engine computers sometimes cannot detect another problem if they are dealing with one already. That may be why it didn’t have oxygen sensor faults at first, but set the faults after you fixed the other problem.

The best thing you can do now is to diagnose the issue with the oxygen sensors, as it may not be fixed by replacing the sensors. You also may need to scan the ABS control module, as there may be faults stored in that which are causing the traction control light to be on. If this sounds like more work than you are up for, I suggest contacting a professional technician to have them diagnose the real cause of the check engine light.

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. Check engine, traction off lights are showing

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: Possible fuel injector leak

Hello. If you believe that a fuel injector is leaking, the vehicle should not be driven and repaired as soon as possible since fuel is flammable. You should get the aid of a mechanic to perform an inspection to determine...

Q: What's the best way to check for Evap small leak. I'm getting code P0442

P0442 indicates that you have a small leak in the evaporative emission system. Many times this is caused by a loose or faulty fuel cap. Make sure that the cap is tight and in good condition, so that it seals...

Q: Maintenance light - 2003 Honda Pilot

Hi there. There are numerous reasons this could be happening. The most likely reason a light may come on is that it is due for oil change. If you can, check your mileage since your last oil change and determine...

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...
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 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.