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Q: Do I need to replace the O2 oxygen sensor?

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I have an appointment on Monday, 10/3 to have my car serviced. A mechanic came to my house last week, and did an evaluation and determined the vehicle to need transmission fluid service, the oil serviced, replacement of the front and back engine mounts, and replacement the battery. He said all these things needed to be done ASAP. The earliest appointment I could book was the following week on a Thursday (which was today), and my mechanic pushed the appointment forward to Monday of next week. Today, my car was not getting power. I could turn it on, and I could eventually get it up to 20 miles per hour, but the rpms were going up really high. It was the same issue a couple of months ago, when I had the car serviced at the dealer. They replaced part of the fuel pump, and said I might need an 02 sensor, but got the car running ok. Now, I'm having the same issue.

My car has 160000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. The O2 sensor is...

Hi, thanks for writing in. The O2 sensor is responsible for monitoring the exhaust gases (specifically oxygen content) coming out of the exhaust to determine if there needs to be any fuel adjustments to the engine during operation. When this is not working correctly, this can cause the car to have intermittent power problems which will also cause a fluctuation in RPMs as well.

This issue can also be caused by a vacuum leak, a faulty throttle position sensor or a faulty mass air flow sensor.

When the technician from YourMechanic comes to your home or office, they can also use their scanner to download codes from your car computer to further inspect the issue.

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