Misfire after spark plug change

I recently had my 1998 4Runner 3.4 set p0306 for cyl 6 misfire. Pulled the plug and it had a bunch of gunk on it and was very worn out. Put one new plug in and misfire went away. Decided to do all of them. I did valve cover gaskets, ngk 3967 double ground plugs and new wires.also cleaned throttle body while it was off. Got it all back together but now once it warms up it misfires at idle and set codes P0300 and p0301-p0306 misfires on every cylinder. Any ideas what to check first? Thanks for any help

 

Guessing plugs or wires, since you replaced all. You could try swapping old wires back in, then plugs if not fixed. Even one at a time.

 

Do you know if I had a single cylinder misfire if it would set other misfire codes for cylinders that aren’t actually misfiring? I had that on a Honda v6 on time, it was one failed coil but had set a misfire code for every cylinder

 

I left the pcv hose disconnected smh