Dewaterb

"Hello I recently purchased an 03 chev s10 v6 from my brother, before I got it from him, it had a rich code he was told it was the O2 sensor so he replaced all of them and reset the light and code never went away so I bought it anyway, so I replaced everything, I could think of that might make it run rich, and code still popping up, Stuff I replaced so far, plugs, wires, cap, Rotor, spider injection assembly, intake manifold gasket, Plenum gasket, all O2 sensor, fresh oil change, I took it to the dealer to get it smoged But it didn't pass, because the drivers weren't reset yet, past other than that and the tech said it wasn't running rich so I'm not understanding why the code is still coming on, especially after I replace all this stuff any help will be greatly appreciated thanks in advance