So I got a 99 Camry with 3.0 and auto trans, mostly good, throwing 02 sensor bank 1 sensor 1, not the main concern right now. When the headlights are on and you use the turn signal the trans slips, reverse light and both turn signal bulbs blink, also hazards make trans slip and reverse blink with lights lights on.
multi function switch?

 

Check for low voltages.