well, finally took my truck to ford to find out what was causing the rough idle at the stop light. it turned out to be my upstream bank one O2 sensor. the AC drain hose was missing, and the water is dripping on the O2 sensor. ford wanted $350 to install the O2 sensor and the hose. i told them i'ld do it myself.

i got the O2 sensor from napa for $51, and the drain hose from the dealership for $17. now i can't figure out exactly how the hose goes on. it is a molded hose. if someone could share some light on this that would be great. i'm thinking it goes on the firewall close to the cat converter, but i could be wrong. i know it goes on the passenger side somewhere.

 

its a 4.6L. i have the part number to the hose. 2L1Z-6758-CA is the part number i guess. it has a location number also: F1235A.
hopefully, someone with a parts cataloge and diagram could help.