Is it obligatory to follow a particular madhhab?
Which of the Four Imams (Madhab) a Muslim Should Follow?
Is it necessary to follow any one of the four imams
The obligation of following one Imam? – Youtube Islamic Academy | Ask Abu Saif
It is not mandatory. There is a difference between the concept of Imam in Sunni and Shia understanding. According to Sunni understanding the religion was completed during the life of Prophet Muhammad. So any Imam after that is a teacher, you can agree with him or disagree with him.
Read the Quran Tafseer Ul Quran By Abu Saif
Here in The link Below:
►Tafseer Ul Quran – Al Ehsaan