2003 Mitsubishi Eclipse Q&A

2003 Mitsubishi Eclipse Question: witch side is bank 1

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. -
Answer 1
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. Roy -
Answer 2
the bank on v6's and v8's indicate which manifold the sensors are on.....bank one is always with cylinders 1-3(v6)/1-4(v8) there are 2 sensors on each bank ....one 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. -