Skip the auto shop - Our mechanics make house calls

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?

A: The Check Engine Light is likely still on d...

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 1000 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!

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: Tire pressure light check

There are a few different types of tire pressure monitoring systems in the car. Some just show you when a tire is low, some show individual tire pressure, and some will tell you exactly which tire is low. The Lexus...

Q: Knock sensor keeps setting off

I would recommend clearing the P0328 code and then see if the code returns. If the code returns and the engine does not have any knocking noise, then test and replace the knock sensor and retest the system. If the...

Q: What does the immobilizer light mean?

When your engine is turned on, the immobilizer light should briefly turn on. This lets you know that the security system is working; if the immobilizer light does not briefly come on, the system is not functioning properly. If the...

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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.
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.