B2S1 and  fuel to rich?

I have a 2006 Chevy Silverado 1500 4.8L. I bought from a guy who at the time was driving it in 2nd gear. After purchasing, I installed a used transmission which fixed that problem allowing me to drive and reverse again. 

Right after fixed trans another light emerged, cylinder 3 misfire. Replaced nasty spark plug/coal and all wires. Soon ignition light cat convertor not working correctly. Replaced with 2 new cats. Soon after an insufficient switching on B1S1, then 2, etc. Replaced all 4  02 sensors. 

 I got to CAT on drive cycle and more codes. Insufficient switching, rich to lean code. I installed new pressure sensor, MAP sensor, coolant temp sensor, and nothing 

Engine starts slow now. So, after several smoke test, fuel injector tests and changing all 8 fuel injectors I replaced fuel pump it starts fine but still B2S1 insufficient switching/ slow response and fuel to rich. Bought a new computer still O2S1

I can't get inspected due to COVID-19 but as soon as 19 clears way I have to get inspected. Please help. 

 Thank You,



1 Answer

  • Anonymous
    1 month ago

    Check B2S1 O2 sensor heater circuit.  Disconnect the connector to B2S1 and connect a headlight bulb test light to the two wires with the same color (could be both black or both white).  Check if test light lights up with key ON (or engine running).  Test light should light.  If test light does not light check for wiring from one wire to fuse and one wire to ECU.  If test light lights up, you need to see a mechanic with a scope to check B2S1 voltage signal output.  Signal or ground wire could be bad.

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