Hesitation while driving and stalling while idling

For about a week started off by stalling during idle then about another week later it started hesitating while driving or bogging down like it wants to stall. The engine light is on, but when it starts to hesitate the light will flash. I took it in for a oil change and to have them check and see what was wrong. They had it for almost two days and during that time it did not do either of those things. They hooked it up to two different dynastic scanners and both said crankshaft positioning sensor. They did not replace it due to the fact it never did what I said it was doing while they had it. I also replaced the crankshaft and camshaft sensor seven or eight months prior to that due to a non starting issue I had and again the code was the same, but it ended up being (I do not recall the exact name) but the electronic modular sensor. So due to that I do not know if I 100% trust the scanner. So if anyone has any ideas on what it could be please help me out. Thank you.