O2 sensors
Asked by Kyleb1979 Mar 28, 2019 at 09:57 AM about the 2012 GMC Sierra 3500HD Chassis SLE Crew Cab 4WD
Question type: Maintenance & Repair
Check engine light came on and the codes were for
the O2 sensors, so I replaced all 4 O2 sensors and
is still throwing multiple codes for the 02 bank 2
sensors, any ideas as to why?
4 Answers
What is engine size? Can you post the code number? Was the only codes, bank 2 sensor 2? Check sensor wiring circuits, check sensor heater circuit where applicable. You may need to check the cat? Also, check fuel trims to see if running rich or lean? Just my opinion.
Has a 6 liter in it and the codes are P0138, P0140, P0158, P02271, P02275, P0160
The codes are bank 1 sensor 2, bank 1 sensor 2, bank 2 sensor 2, bank 1 sensor 2, bank 2 sensor 2, and bank 2 sensor 2!
Sirkut_Interrupted answered 5 years ago
These are codes the downsteam o2 sensors.. high voltage on the signal wires which means either a short to power on both sides or you bought sensors that are wired wrong and the heater circuit is going in the signal circuit.. p02271 and p02275 are reading rich bc of the 12v going into the signal wires