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Witch side is bank 1

(2003 Mitsubishi Eclipse)
in Lexington, KY on April 17, 2011
the check engine light is on and it said the o2 sensor on bank1 sensor 2 . I replaced it and the light will not go off I am trying to figure out if i replaced the right side.
the o2 sensor i replaced is on the bottom in the front.
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Popular Answer
on April 17, 2011
the bank on v6's and v8's indicate which manifold the sensors are one is always with cylinders 1-3(v6)/1-4(v8) there are 2 sensors on each bank upstream of the cat and one downstream...sensor 2 is downstream.. the two cats that are bolted to the manifold are oxidation beds. The upstream o2 sensor (sensor 1) is located in the manifold, and it reads A/F based on the oxygen level present in the exhaust. The oxidation bed (pre-cat) then oxidizes, and removes all but around .2 percent of the o2 in the exhaust. The downstream is the sensor 2 on each bank. It is located after the cat and measures the change the cat causes.
on April 17, 2011
first of all, a code never identifies an bad part just a failed system. you need a flow chart for the code to determine if it is the wiring, a blown fuse from the heater, a bad pcm or something else causing the sensor to fail.
it can get expensive throwing parts at it.
let a shop help you with the diag so you know what the exact issue actually is.

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