2007 GMC Yukon XL O2 Sensor Faults: P0131, P0151, and P2119 - Low Voltage Issues After Throttle Body Replacement
I own a 2007 GMC Yukon XL that has recently triggered fault codes P0131, P0151, and P2119. The diagnostic indicates low voltage in the oxygen sensor circuits for both Bank 1 and Bank 2. After replacing the throttle body yesterday, my vehicle began spitting and sputtering within five minutes, resulting in a limp-home condition. I'm wondering if faulty oxygen sensors could be causing this erratic behavior. Does 'low voltage' on the O2 sensors mean they need replacement? Any guidance or troubleshooting steps would be greatly appreciated. Thanks for your help.
No other fault codes are present, and this is not an AFM-equipped engine; vehicle is stock with no modifications. Codes P0137 and P0151 indicate pre-catalyst oxygen sensors showing low voltage. First, verify the actual sensor voltage—does it remain stable or can it be raised (by enriching the fuel mixture)? Also check the fuel temperature (FT) and manifold absolute pressure (MAP) sensors. A lean-running condition could cause the O2 sensors to register low voltage. Has P2119 reappeared after the throttle body replacement? Did you perform an Idle Learn Reset procedure following the TB change?