I've got a 96 burb 4x4 5.7 vortex. Just recently had the head gaskets replaced. Lately it would start losing juice in the alt to where it chokes out and dies. Replaced alt, battery, o2 sensor. Check engine light keeps coming back on. When checked it implies o2 sensor.My question could the o2 sensor cause the alt to be drained while driving? Any help would be appreciated thanks in advance.

 

Only the battery can be drained per se but the alternator could be shorting out or not charging the battery at all...
check your cables esp the ground cables to the block and chassis they need to be clean and solid and no corrosion same goes for the positive cable to/from alt to battery....

 

If work was just recently done and this starting happening I would also check all wire harnesses for any pinched wires and check also that none are shorting out on the hot exhaust manifolds. tidy up under the hood with some wire ties....

 

Thanks for the info. Am in the process of checking all wiring. Thinking it might be related to brake wires, due to oil and temp needle jumping when brake pedel pushed in