2000 GMC Sierra 1500. Code P1154, replaced all 4 O2 sensors. Same code came back

Question

2000 GMC Sierra 1500. Code P1154 replaced all 4 O2 sensors. The same code came back. Do I have a bad O2 sensor?

Answer 1

Every 1 assumes whatever part the code talks about is the root cause for setting the code, but this is a very expensive way of thinking and the wrong way to go about diagnosing the root cause as you have found out.

 Code P1151 may mean that one (or more) of the following:

Electrical:

• Short to VPWR in the harness or HO2S
• Water in the harness connector
• Open/shorted HO2S circuit
• Corrosion or poor mating terminals and wiring
• Damaged HO2S                                                                                                                    (New faulty/Aftermarket HO2S)
• Damaged PCM

Fuel System:

• Excessive fuel pressure
• Leaking/contaminated fuel injectors
• Leaking fuel pressure regulator
• Low fuel pressure or running out of fuel
• Vapor recovery system

Induction System:

• Air leaks after the MAF
• Vacuum Leaks
• PCV system:
• Improperly seated engine oil dipstick

EGR System:

• Leaking gasket
• Stuck EGR valve
• Leaking diaphragm or EVR

Base Engine:

• Oil overfill
• Cam Timing
• Cylinder compression
• Exhaust leaks before or near the HO2S(s)

Answer 2

P1154 CHEVROLET - HO2S Transition Time Ratio Bank 2 Sensor 1

Read more: https://www.autocodes.com/p1154_chevrolet.html