So I replaced all the vacuum hoses today. Although it did not fix the issue with the check engine light coming on after about 2-5 minutes of driving (KOEO 332), there is a very noticeable improvement in performance in terms of better acceleration at start, so just for that it was worth the effort. Those old brittle nylon hoses were shot. So will be inspecting the EGR valve and sensor carefully this weekend. Thanks for all your help.

(1995 F-150 4x4 5.8L)

 

Replaced all vacuum lines and Vacuum reservoir (pretty rusted) as mentioned, CEL still came on. So I bit the bullet replacing the EGR valve, EGR sensor and EVR (got 30% off at Pep Boys so sweet price for all three -why not?). So I replaced everything yesterday. It was getting late but I wanted to take that bad boy out for a test drive. A few minutes into the drive BAM! The CEL comes on again. Also, the beast under the hood didn't seem to have the same pep it did the other day. So, I went home ran codes and sure enough, 332. So I sulked back into the house, re-reading the diagnostic manual and all the forums again to see what I might have missed. Went to sleep. Next morning, I went out and just to be sure, checked the vacuum lines. Well I'll be damned...one of the little black hoses pulled out. Must have happened when I changed the EVR yesterday (it was getting dark). Soooo, I made a little longer piece of tubing and replaced it, and went out for another test drive. After driving for 20-minutes no CEL.

Morale to the story, when everyone on the forums say check the vacuum tubes...check 'em. Thanks to everyone on the forums! That is all.

 

Thanks for replying back with the resolution!