Any one else having this check engine light?

[f5fstop]

Yes, did you get a new cylinder head?
Just a note to everyone, you can drive upwards of 5K miles with this problem with the cylinder head. All that is happening is one of the intake valve guides (usually in cylinder number 1, but can be any cylinder) has elongated, and causing a misfire. The misfire is picked up by the knock sensor and thus the 300+ code(s) is set.
The idle will get worse, but the engine will continue to run, and the only damage being done is to the cylinder head, which has to be replaced anyway.