Out of the blue the headlights went out I got some new ones and within a few moments of being on they went out it was like they burned out on low beams and then put them on high beams and then they burned out on high beams.

we have done a full tune up, changed fuel filter, fuel pump, throttle body gasket ,cadillac converter, map sensor, i know there is probably more but it runs like a heep still.. Back up, it stalls,, stop anytime and go to take off,, it stalls.. its popping and fartin and just sounds BAD! Sad thing is we just got it back from a mechanic.. What could it be?? Please help!

transmission does not shift into overdrive. the light in the switch is off, pushing the switch in does not change anything, is there a overdrive switch relay that could possibly be bad. If so where is it located?