silasmoeckel:
Well that gas sensors heater is rated at a 350ma draw
No, it is rated for 350mW. Power, not current.
The coil has a resistance of 33ohms. So during the high cycle (5v) it will draw 160mA for 60 sec and the low cycle (1.4v) will draw 40mA for 90 sec. This gives an average (engrish: about), 350mW.