Fussy fuel injector

I been having an issue with inj #7 (driver side rear). Last fall before putting it away for a winter nap I got a p0200 & p1222 code. With it running I could feel all the injectors pulsating except 1. Checked the voltage 12.5?. I assumed faulty injector. Replaced it. Drove it for a couple weeks and no issues. Pull it out in spring and after a couple weeks of driving same issue. I just bought a cheap one from rockauto the first time so I thought it was garbage So I replace it again with a new one and the car ran out great till today. Same crap, no pulsating but there is 12.5? volts. Checked the codes p0200 p0300 p1222 p0200. What am I missing?

FIXED!!! The hot going to the injector had a bad spot in it. Everytime I would disconnect from the injector it'd have voltage. What a pain.