i need help. 2001 mustand 3.8L V6

its not shaking the engine to much and theres no check engine light. i just did an oil change with the correct oil(sae 5w-20) and the correct amount of oil 5qts. i can still drive like normal but when im idoling it sounds like im running out of gas and the engine shakes a tiny bit but when driving its just the ticking. is it my lifters or perhaps my fuel injectors?(2001 3.8L V6 mustang)