So I got a 6.1 hemi in a 2013 300s and it’s missing on cylinder 1 I replaced plugs and coils still doing it it’s giving code p0301 Can’t seem to figure out what it is any help? Thinking it was the mds selonoid

 

Try moving the coils to another cylinder, see if the miss follows the coils.

 

So you absolutely do not have a 6.1 in a 2013 unless you (or someone else) has done some serious wiring surgery. So it's either a 5.7 or a 6.4. Perform the above to see if it moves or not. If not, then a compression test is the next step. If the actual solenoid for cylinder 1 was messing up then the code would be different and specific to that. What could possibly be happening as that you are in the midst of lifter failure; is it just a misfire or is it accompanied by a rather loud concerning tick?. Only way to know for sure is borescope and/or teardown to see if your lifter is failing and if the cam has been damaged or not.