PO155 check engine code (O2 sensor)

Tripp

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Hello, This is my first check engine light I've gotten since I bought my car.
It reads

PO155
$0010 1/1 Generic

O2 Sensor Heater
Circuit Bank 2
Sensor 1​

Ive gathered this is
Bank 2 (Left side)
Sensor 1 (Before cat)

Does anyone know where this sensor is, if perhaps there's a reference sheet where I could look for this sort of thing.

My car has a cat delete by the previous owner. Hope he didn't screw up too hard.


I've attached a picture of my cheap generic scanner.

Thanks!
 

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white95

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That is the driver side, upstream oxygen sensor. The upstream sensors read check the oxygen content of the exhaust to determine the AF ratio.

Cat delete

The downstream sensors are what “check” the function of the cats and, if they were turned off in the tune, aren’t to be concerned with.
 

lwarrior1016

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Sound like you have a bad sensor. With that code, it can sometimes be wiring but most of the time it is a bad sensor.
 

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