If one is davening with a minyan but is a little behind, what is the halacha with regards to “kel melech ne’eman before shema? should he say it or not?
Because he is in the framework of a minyan, and hears the final words of the Shema recited out loud from the chazan, Kel Melech Ne’eman should not be said.
Note that even for davening without a minyan, there is a debate among authorities over reciting Kel Melech Ne’emen (the reason not to is for fear of interruption), which is another reason for leaning towards not reciting it when davening with a minyan, even if one is a little behind.
An interesting question will arise when the chazan says the final words of Shema out loud before one reaches the beginning of the Shema. Even for this case, however, my leaning is that Kel Melech Ne’eman should not be said, for one still hears the words. However, I have not found an explicit source that discusses the question.