2000 GMC Sierra oxygen sensor low voltage

160,000 MILES • V8 • 4WD • AUTOMATIC
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SMOREY
  • MEMBER
  • 1 POST
my truck has an oxygen sensor low voltage trouble code, it's bank 1 sensor 2, this is driver side after the cat. i changed the sensor and still have the problem, i have a programmer so i can read the voltage, i'm not getting anything above 100mv unless i really rev the engine. i have checked the connectors and i'm getting 12.9vdc to the plug between the +12v (pink) and the negative (black). It seems like i have a wiring problem between the connector and the PCM. I'm at the point where i'm about to run some new wires between the sensor and the pcm. I've pulled off the pcm connectors and used contact cleaner but i still have the problem. i have also swapped oxygen sensors bank 1 and bank 2 and the problem stays on the same side, so i know it's not a sensor problem. I'm running out of options and i can't find any info on this issue. I appreciate any help that can be given.
Jan 26, 2008 at 5:44 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
You're getting the low voltage bcuz you have a high 02 content on that bank and the computer dumping fuel at it to compensate-try looking for a vacuum leak and check the EGR if its leaking.
Jan 26, 2008 at 7:33 PM
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