Look four posts above yours.

 

oh...my bad

 

When you get a p/s pressure code and this for the 4.7 motors, Be sure to clean the connector with brake clean and compress air. Because the p/s fluid will leak into your wire harness and short out one or all of the o2 sensors.

 

I had the same problem with my truck and it was a leaky power steering rack, i had a hard time finding any kinf\d of rebuild kits and then a site that the exact kit I needed for really cheap (like $10) they also had an online diagram and great instructions!!! if anyone else has this problem they might wanna try this site!!
www.pskits.com