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・Save up to 30%

Get a quote

What others are asking

Q: My car has several misfire codes and does not run properly.

Hi there. What prompted you to replace those particular parts? Did testing reveal a fault? This year model, along with its sister IS models, up to 2011 had a service campaign for cylinder misfires. The campaign did not cover the...

Q: Check Engine Light came on

You need to have the purge valve checked to see if it is flowing vapor from the fuel tank when the engine is at idle. The flow will cause the engine to run too rich and can cause the cylinder...

Q: Battery light is still on after getting a new battery and alternator

The Honda Element has a computer-controlled charging system to help improve fuel economy. In the engine compartment fusebox there is an ELD unit that monitors electrical loads of the vehicle consumers and will communicate with the engine computer to turn...

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 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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...