have miss fire codes cylinder 2-4 ...replaced plugs, coil pacs,fuel injector..still has a miss.. only has 157,000kms can it have bad valves or am i missing something too check? possibly timing belt shifted im confused Thanx in advance

 

I'm curious as too what you find out....although I'm in the muddle of replacing the thermostat, my 2003 has multiple missfires as well as p1471 1472. This point to stuck valves in the intake plenum. Might be motors? Or plenum? I'm taking it one step at a time!
Good luck!
Joe king