It never ends! More codes.

[checkedout]

CEL came on yesterday, P0304 and P0153.
Checked the plug and wire on #4 and they looked good. Both are only a couple months old and Motorcraft. Oils fine, coolant is not going anywhere and it's running fine. I was hoping to see the wire melting to the back of the EGR, but it's fine. Just once I would like something to be easy.

 

[Opera House]

Check that plug again!

I would venture to say that there is probably a little more of a coating on one side than the other. I suspect lower intake gasket problems and that you might be loosing small amounts of coolant now and then. #4 is a common problem area and the 153 indicates the O2 sensor is being poisoned.

 

[checkedout]

I just had the heads replaced in October. :-(