O2 Sensor is Reading Funny

[guc32]

I have a custom turbo kit and have put my O2 sensors in my 3in full exhaust. I have an OBD2 scan tool and can see how the sensors are reading. One would read 20% and the other would read -20%. They would fluctuate when i drive, but they will always be opposite of each other. And this keeps throwing check engine lights. Shouldnt these readings be the same on both of the sensors? Do i have a failed sensor? I have extended the lines on the sensors because i had to move it futher back then it was before. Would that have cause the readings to be different?

Thanks Yih-Woei

[stimpee]

Well, based on your comments, what are the chances that you swapped the wires when extending one of the sensors?

Steve

[guc32]

Hum That is possible. Ill check that tonight.

[guc32]

One thing i didnt state is that it will read good at first then it will then read opposites. Or not even close to each other.

The check engine is always for the second bank sensor, so when i switch them up top where the connection is, the bank 2 sensor is always the bad one.

[///3oris]

What are you using for software? :devillook

Boris

[guc32]

I dont have software.

[guc32]

If the readings are off by a lot, does that mean one of my sensor is gone? But they read fine till i after they warm up.

[BenzTech]

Your sensor readings should fluctuate from .1-.9 V. Are you running a cat?
What does your short and long term fuel trim percentages read?