# Code PO138



## zcar75 (May 20, 2002)

I ran the codes on my 98 200sx ser and came up with P0138. High voltage from rear O2 sensor. Does this mean the connections is bad or the sensor is bad.....thanks


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## 0341TODD (Nov 15, 2003)

huh? man explain b/c you are confusing the heck out of me. I dont know if anyone else will know what you mean either.


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## Zen31ZR (Mar 24, 2004)

0341TODD said:


> huh? man explain b/c you are confusing the heck out of me. I dont know if anyone else will know what you mean either.


Don't worry man it's OBD-2 rules , so it's supposed to be confusing.  
But just from the general description I'd say we're talking about the 2nd o2 sensor thinks the cat is letting too much unburnt gases through. This could indicate cat failure , the car is running way too rich ...... who knows. OBD-2 is not my specialty.


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## Nismo1997 (Dec 26, 2003)

I own a obd2 also. The sensor itself got to be bad. nothing too big. good luck with it.


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## 0341TODD (Nov 15, 2003)

The cars on this forum arent anywhere near obd2 though- that wasnt till like 97 that they switched over right?


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## Zen31ZR (Mar 24, 2004)

0341TODD said:


> The cars on this forum arent anywhere near obd2 though- that wasnt till like 97 that they switched over right?


 96-97 , somewhere in there. In any case , yeah , this was posted in the wrong forum.


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