How do I fix the code P1399?

Question

I changed all sparkplugs and when i turned it on at first it said misfire cylinder 2&3&4 and then again i checked and now its a hard start and The code itself. Is there ? Why

Answer 1

Something happened during the tune up , P1399 is random misfire it usually with the valve adjustment , If this engine has a distributor cap the firning order can be wrong, if it is Coil On Plug the placement can be in the wrong place.