I have replaced the fuel /oxy. sensors in my 2000 sonoma 4x4 6 cly. Once it warms up, it again idles rough and i get the "rotten egg" smell .It gets worse the longer it is driven. I have had the fuel pump replace this past summer . The new sensors are less than 2 months old. What gives??? :banghead:

Welcome to AF, any codes that led you to the 02 sensors. Possible that the Vortec injector assy is leaking, common problem, could be the coolant temp sensor is holding the engine in open loop rich function. What diagnostics or checks have been done to check this out so far?