On the question, "Does God hear the prayers of sinners?" we need to
distinguish.

If we say that He never hears the prayers of any who have sinned, we
make pointless all prayers by anyone born less than 19 centuries
ago.

But if we consider the prayers of the impenitent sinner, of someone
who says, "Lord, I want you to do this for me, but don't expect me
to change my way of life," that is a different matter. Even here, I
would not venture to say that God never grants such petitions (just
as He sends sun and rain on the evil and on the good). However, if
someone we know well is praying to God in that spirit, we might have
the responsibility to say, "Remember, if God's help is real, then so
are His commands."