HP OfficeJet Pro X451dn Leftmost Printheads Printing Wrong Colors

[churipputori]

I've recently obtained a OfficeJet Pro X451dn printer that went through shipping without proper shipping preparations. When I had set the printer back up, the print quality report was initially pretty bad, however after a level 1, 2, 3 cleaning, a waste tray replacement, and two printhead recoveries (via tap 23 test), the print quality is perfect for most of the page. Now, it looks that the two leftmost (in respect to page orientation) printhead dies have all four colors off, and the two after that have only yellow off. After a bit of printing, I had done another print quality report (the fifth so far) and it appears that the colors are slowly clearing up. Should I keep running cleanings or printhead recoveries, or should I just leave it and hope it clears up on its own after a few prints? Thanks.

p.s. I am using all genuine HP ink. 

Update: I made a image of repeating CMYK bars on the problem side. It seems that after a few prints, it's slowly getting a bit better. Should I just keep printing color bars so that it'll hopefully go back to normal? I ordered another set of ink, just in case i need to run it so much that it uses up all of my current set.

[churipputori · Accepted solution]

I found out the solution! Basically, I had just made a document that had a solid color bar spanning the length of the troublesome printheads. After about 20 pages of solid color, the bars have completely cleared up and the printer prints nearly perfect again! Hopefully anyone who gets here from Google finds this and it works for them.