Just did my first 6.0 oil change today. I used an OEM filter. The directions that came with it said to replace the o-ring on the "reuseable filter cap". My filter cap says "Do not reuse cap". (It's not OEM, it says NAPA on it)

Cap looked just fine, so I replaced the O-ring and reused it. Is there any reason I shouldn't?

 

It will not allow the filter to seal inside the housing correctly and should NOT be used with an OEM filter. Go to Ford and get a new OEM cap. Aftermarket filters can and will cause all kinds of issues.

 

OEM cap is on the left in this picture.

 

Immediately run over to ford and buy a new oil filter cap. In fact, your filter is now sitting loosely in there, not doing its job. Injectors are expensive but the cap is dirt cheap to replace.

 

Mine had an aftermarket cap on it when I got it. Couldn't even get the old filter off the cap without breaking it. Got a factory 1 first thing and no more problems.

 

ford told me if i used a aftermarket cap it could void warranty, had egr issues at 60k truck now has 116k and its going in for a hysterectomy of the emmissions lol and a programmer

 

Well this is already answered but......OEM Cap's only