# 99.5 A4 2.8 Oxygen sensor woes



## Kentium (Oct 1, 2007)

Hi,
I just replaced both of my after-cat oxygen sensors and I'm receiving different codes than before. It used to be no activity and heater malfunction on both and now I have a heater malfunction still but it's a different code for each. 
Codes are (descriptions from Bentley)
P0138 (DTC 16522) O2 Sensor Circ.,Bank1-Sensor2 High Voltage
P0157 (DTC 16541) O2 Sensor Circ.,Bank2-Sensor2 Low Voltage
P1198 (DTC 17606) O2 Sensor Heater Circ.,Bank1-Sensor2 Electrical Malfunction
P1199 (DTC 17607) O2 Sensor Heater Circ.,Bank2-Sensor2 Electrical Malfunction
Are the new sensors bad or is it possible that the wiring to the plugs under the hood are bad?
Any thoughts?
Thanks


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## mardimus (Apr 21, 2007)

*Re: 99.5 A4 2.8 Oxygen sensor woes (Kentium)*

Did you ever figure this out?


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