2004 Lancer idle issue please help...
 

I have an issue with my 04 Lancer when turning on, especially in the cold weather. When it turns over and starts, the RPM shoot up as normal to 1.5-2k, then back down, but it goes too far down and the car turns off. Seems like whatever is supposed to be holding it "up" at idle is not doing so and the car turns off. Giving it a little gas right after turning on, simply to keep the RPM up above 500-700, will make the car stay on. You need to give it gas for about 3-5 seconds or so and it idles fine then. So far I've replaced the valve cover gasket, spark plugs, wires and checked timing belt which looks ok. Any advice would be greatly appreciated, even to just point me in the right direction on where/at what to look. Thanks in advance.

Oh and this is more prominent in the cold, whereas when it's warmer out most of the time it turns on just fine.

Check all your fluids . Starting fluid etc.

And check your coolant . Hopefully none of you fluids freezing .

sounds like a ghey sensor.
MAF, thermo, TB, knock, something. i always advise an ECU reset.