Got a PO353 and a PO356 what does this mean on 1999 Ford Expedition

Changed Coils all 8 and spark plugs
Didnt have this problem before
Also getting a misfire

Asked by for the 1999 Ford Expedition
2 answers 3 comments
should get compression check. possible may be loose spark plug or fouled threading. these engines have a shorter thread count which has caused several issues varying from vehicle(spitting plugs, spark plugs snapping during extraction, thread slots that are brittle and prone to cracking, etc).
Thanks it was one of the spark plugs and one of the connectors
Thanks again!!
Check wire connections at coils # 3 & 6 possible damaged, loose connector. Check for cracked spark plug insulator, same cylinders 3 & 6.
# 3 is 3rd cyl from front on pass. side, # 6 is 2nd cyl from front on drivers side.

 
Thanks it was one of the spark plugs and one of the connectors # 3
Thanks again!!
Cool, U welcom.
We try!