flathead1950

i own a 05 f150 5.4triton 121,344 miles just 2 days ago on dash it said CHECK GAUGES evrytime i started it up then goes away,its started to run like it out of time then goes normal,till yesterday otw to work it sounds like a diesel,then engine light came on,codes were poo21,po174 poo21,po174,po340,i changed bothcmp sensors and still sounds like a valve slappn,till i kinked the pcv vavle hose then the knocking almost stopped,i took it out and can see light from one end to the other is that normal,i figured there was a check valve in there ,or did it get sucked in my intake,also now my oil pressure gauge is the only one not working,i unpluuged and removed the sending unit,had buddy turn motor over oil shot out any help greatly appriciated

R.S.LOGAN

When was oil and filter last changed ? Could check oil pressure with a master gauge and see what it reads .

f250alex

i have this same kind of problem on my 2006. I started a thread about it as well, but this one kind of explains it a bit better. Hoping to hear what it may be.

Bluegrass

The 340 and 21 are telling you the camshaft position sensor or it's operation has an issue.
The 174 is an OX sensor telling you there is an 'intake' air leak of unmetered air causing fuel tables to be shifted out of range or lack of fuel. Either one will cause a table shift trying to correct the problem until it goes out of limits setting the code.
It may be due to the cam position issue because the cam sensor also controls fuel injection for that bank..
The vairable cam timing hardware may have an issue that is causing the noise and the codes.
Good luck.