Q: Why does my oil gauge go to zero when I press on the gas pedal?What does it mean if I have to keep putting transmission fluid in?

The oil pressure gauge will fluctuate slightly with changes in engine RPM’s, but should not go down to zero. This could mean a few things could be happening. Either the motor is in fact low on oil, the oil pump could be failing or not pumping oil sufficiently or the oil pressure sending unit is not working properly and may be producing a faulty reading. If the engine is in fact low on oil, you may notice the temperature gauge reading above normal temperatures as a result of the lack of sufficient oil in the motor. I would recommend checking the actual oil level in the motor by using the dipstick. Be sure the oil level reaches the "full" mark. If this registers as "full" then you likely have a faulty oil pressure sending unit.

The issue of the car jumping when sitting at a stop light related to putting transmission fluid in it could likely mean the car is low on transmission fluid, which may cause the lurching symptom you describe. It sounds like your vehicle may be a bit low on transmission fluid or you may potentially have a bad transmission control solenoid. As you know, the transmission works on hydraulic pressure built up from the fluid inside and uses this pressure to activate solenoids that cause the transmission to shift. When these are not working properly or when you have low transmission fluid, this does not happen which usually results in erratic shifting patterns, a jerking reaction or in some cases no shifting at all. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.