• Auto Parts and Repairs
  • Oxygen Sensors
  • Check Engine Light
  • 1995-2005 Chevy Cavaliers

Which sensor downstream or upstream causes the MIL light to come on?

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Answered 2004-11-22 10:13:00

About 30 things can cause the light to come on. TAke it to auto zone and have the codes read for free.

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How do you know which oxygen sensor is bad in a 2002 Dodge Caravan?

Get the check engine light looked at, the code will specify if it is the upstream or downstream sensor. The upstream will be on the exhaust manifold, and the downstream will be on the pipe after the catalytic converter.

Where is the upstream oxygen sensor located on a 1999 Ford Taurus SE with a 3.0L V6 engine and how do you go about changing one if only the upstream is bad do i need to change the downstream as well?

The upstream 02 sensor is usually located shortly after the exhaust manifold, before the converter. That is the one that controls how the car runs. The downstream sensor, after the converter tells the computer if the converter is doing it's job or not. It does not affect performance, but you might have to live with a check engine light being on. There are probably 2 of each on a V6.

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