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Q: Check engine light illuminted

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The dashboard in my car showed check engine light on. I was told that the O2 sensor should be replaced. After having the oxygen sensor changed, the light went off. However, the following day, the check engine light went on yet again. What could be the problem? I appreciate your help.

A: Depending on the code received, you could e...

Depending on the code received, you could either have separate problem or the O2 sensor code returned due to a misdiagnosis. The codes for O2 sensors can be from the engine running lean, rich, misfiring, or several other reasons. However, it is not caused by a problem with an O2 sensor itself. Have the computer scanned and see if the same code returns. If it does, then a proper diagnosis should be done to fix the real problem. I’d suggest getting the vehicle serviced by a qualified technician who has the tools and experience to diagnose your Check Engine Light. A proper repair can be made once the issue has been pinpointed.

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