Q: Check engine light spontaneously comes on

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The check engine light on the instrument panel keeps spontaneously coming on. Soon after this warning light illuminates, my car started jerking forward. This happens at various speeds; I have not noticed any pattern to the speed. I went to an independent mechanic, but he could not duplicate the problem so he couldn't repair it. In your expertise, what is causing this problem?

Hi there, thanks for writing in about your 2003 Geo Tracker. There are numerous potential causes for the problem you are having. It could be anything from a bad spark plug to a failed sensor. The only way to know for sure is to have the vehicle diagnosed while the it’s acting up and the Check Engine Light is on. This will allow for retrieval of the stored diagnostic trouble codes (DTCs). These codes serve as a starting point for any further diagnostics. If you need help, a qualified technician from YourMechanic can take a look at the car for you.

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