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Anthony, GMC Technician
Category: GM
Satisfied Customers: 11751
Experience:  GM Certified
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2000 GMC: liter engine..few miles..check engine light comes on

Resolved Question:

I own a 2000 GMC Sierra 2500 with a 6.0 liter engine. It has been diagnosed that right side O2 sensor, after the catylic convertor has low voltage. I have replaced the O2 sensorXXXXXit for a few miles and wham the check engine light comes on. The truck has 80000 miles on it. I've taken it to the local GMC dealer for the fourth repair and they diagnosed the same problem and told me the O2 sensor I purchased was bad. There must be something else wrong that's causing these to go bad, if they are truly bad.
Can someone help me put this nightmare to bed.
Sincerely XXXXX XXXXX you,
Jerry Mason
Submitted: 7 years ago.
Category: GM
Expert:  Anthony replied 7 years ago.

Hello! Welcome to justanswer!


Do you know what code keeps comming back?

Customer: replied 7 years ago.
Yes the code was PO157 HO2S B2S2
Expert:  Anthony replied 7 years ago.
Ok, if you have replaced 4 sensors and the code keeps returning then you have a bad engine computer or wiring. Do you want the complete troubleshooting chart for that code?
Anthony and other GM Specialists are ready to help you
Customer: replied 7 years ago.
Is it difficult to change out the computer?
Expert:  Anthony replied 7 years ago.
Not at all, a 5 year old with a wrench could do it. Do you want the procedure? You can get one pre-programmed from any autoparts store.
Customer: replied 7 years ago.
Can you tell the location of the engine computer?
Also what is the exact termology for the computer. Is it ECM
Thank you
Expert:  Anthony replied 7 years ago.
The engine computer is right near the battery and has fins on it. Yes it is the ECM also.
Customer: replied 7 years ago.
Hi Anthony,
Can I still get the complete troubleshooting chart for the codes I    sent you yesterday.
Thank you, jerry
Expert:  Anthony replied 7 years ago.

Sure, no problem. See below: