2009 Honda Pilot throwing p3400 after rebuild

Hello,

I have a 2009 Honda Pilot currently at 117k miles, the engine blew out half a year ago and my stepfather asked his buddy for a recommendation on a mechanic. Well, I've finally gotten the PIlot back after waiting forever, first time I sent it back because of CEL engine misfire codes on bank 2, cylinders 4, 5, and 6. After getting it back the first time, I had P3400 valve pause system is stuck off. I sent it back and I guess supposedly he replaced a solenoid. Lo and behold, I get it back again (and have it now) and it's still throwing P3400. I'm guessing this guy doesn't know what he's doing. Does anybody have any ideas? Apologies in advance, I am very car illiterate.