Car hesitates when in Drive but not in Park or Neutral

engines
chevrolet
camaro

#1

…Its a 3.1L, I just changed my MAP sensor and my O2 sensor. It idles ok. Also cant seem to get the timing just right even using a timing gun and putting it at the right degree it still runs kind of crappy. it says no check engine light even though the light works… i love the car but its been a nightmare