2004 f-150 5.4 . I did install a K&n air filter on and was wondering if this could cause truck to appear to run lean or is this increased airflow small enough to be adjusted for by the computer? These codes appeared when flooring it from dead stop.
Also wanted to let everyone know about an issue we had where the truck was idling too low,dying and running rough. Issue started when I changed my battery. Apparently when you disconnect battery ,the computer resets butterfly in throttle body to 0 no matter where is actually at. Inside the throttle body where the butterfly is, a ring of carbon builds up and will not allow butterfly to seat where it should be giving computer bad information about butterfly position. Just clean the carbon ring off the throttle body and let butterfly seat before reconnecting battery.

 

Don't want that stuff in engine . I have revised throttle body as my electronics on motor failed . 05's had a series of defective ones . You want to use throttle body cleaner as some other stuff will remove coating on throttle body I'm told . My new one was $ 200.
You may need to clean your MAF with maf cleaner .
Look for any intake leak .
If you are flooring the 5.4 too much it is probably going to cause a timing set failure from the chains whipping .
I'm an old guy but I remember the days I did some of that . But that was a 57 ford ,simpler engine .

 

Yes, on the 5.4, without a tune, the aftermarket air filter you have can cause it to run too lean.

Put the stock one back inand see if it goes away.

Re throttle body cleaning: the TB cleaner will remove the coating. The coating is to help prevent any build up. However, of you plan on cleaning it even every so often, the coating wouldn't matter.