My car stalls either after i start it, when i'm stopped or every once in a while when i'm driving.. is this a sensor problem or ventilatiom problem???

Throttle body needs cleaning or Vacuum leaking passed MAF sensor.

Start with the throttle body. I use brake clean and a toothbrush. Clean the plate and were it sits. Wouldn't hurt to spray down the MAF sensor, if it has one. Once you do it, it will take a few seconds to start. Once started, rev it up and spray inside the throttle. Keep it running. Most times this is a $4 fix.

fuel pump,fuel filter,gas cap,injectors,relays,camshaft,crankshaft sensors temp sensor,a number of things,stop wasting money and take it to a mechanic

Hi there : what year make and model, how long do you drive before it stalls? And how long before it starts

Can you hear the starter cranking the engine over?

Have you checked for spark?

Have you checked for fuel pressure?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

I would think maybe the crankshaft sensor but you have no DTC's.So i would check the fuel pressure it could be a weak pump.

take ur car for scanning, get a proper diagnosis.

Although it could be several different things it has the sound of a MAP sensor. Does it ever **** or miss sometimes when you are driving? Does it do it frequently? Has it progressively gotten worse? There are several possibilities, but if it runs fine part or most of the time and stalls for no reason - then restarts - have the MAP sensor checked. I have seen that kind of problem incorrectly diagnosed as a TPS (Throttle Position Sensor) but if it accelerates smoothly it is not likely that.

first try changing the coollant temp sensor

You have a bad crankshaft position sensor. When the thermostat opens on warmup, the auxiliary air pump starts up momentarily which causes a quick dip in battery voltage and drops the output from the crankshaft rotation sensor. the computer thinks the engine is not running and shuts down the fuel. If idling, engine will die, if moving sometimes will just hiccup.