O2 sensors all bad, codes P0135, P0141, P0155, P0161

2000 CHEVROLET TAHOE
265,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
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DANIELLIZ
  • MEMBER
  • 4 POSTS
i can't pass state inspection because i have all 4 o2 sensor codes on and i just can't figure out what to do. I have changed all 4 and the codes came back on within the week. The codes i get are P0135 (Bank 1 sensor 1), P0141 (bank 1 sensor 2), P0155 (bank 2 sensor 1), P0161 (bank 2 sensor 2). Any advice on what i can check?
Aug 6, 2019 at 7:03 PM
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JIS001
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 3,412 POSTS
All 4 oxygen sensors never fail at once. If it is the oxygen sensor heater fault I would recommend you check engine fuse located on position 21 20 amp. If that fuse is blown it will give you heater faults on all 4 sensors.

Since you replaced all 4 sensors you may have another issue. I strongly recommend you use Denso sensors since other brand sensors there resistance can be way off and trigger the light for oxygen sensor heater fault. Check all your fuse especially the one highlighted and let us know what you find please.
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Feb 27, 2021 at 9:40 AM
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DANIELLIZ
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i checked all the fuses and none of them are blown.
Feb 27, 2021 at 9:40 AM
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JIS001
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 3,412 POSTS
Check all the pink wires at the oxygen sensors for voltage with key on engine off and let us know what you are measuring at those connectors. Will also give you a link on circuit testing, how to use a DVOM, and relay testing. Relay could be another issue if you have no voltages at the pink wires. Let us know what you find please.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit



Feb 27, 2021 at 9:40 AM