Ok i'm baffled..I just replaced the oil pan (cut the crossmember) also filled it with synthetic oil for the first time...truck has fuel leak at the return line...anyway it started and ran for about 45 seconds then the idle went to 1500 and the truck started to run really ruff ..it never had a high idle when cold..if i touch the brake pedel it would return to idle then go rite back up then a CEL and stall ...several times..put scanner on and it said no codes.then i got codes..i did notice it is a little over full on the stick.so i removed 2 qts there was never any bubbles on the stick.. .the only electricle parts that were touched in the prosses was i removed the starter and disconnected the batterys...and now she wont idle and runs like its only running on 4 cylinders after about 2 minuets it smothes out but it still idles at 1400 rpm until i touch the brake pedal then it idles for about 10 seconds then goes back up to 1400 rpm...now if i put it in neutural it runs as it should or i unplug the neutural safety switch i changed the neutural safety switch and it made no diffreance i also remembered that several years ago i put in a new switch and also put in a new pigtail i will opean the harness and check the connections ....here are the codes i got out of the PCM

p1280...ICP out of range
P0603...PCM Keep alive Memery
P0344 CPS Intermittent error
P1211...ICP high or low disared pressure

i am opean for any susjestions and appreaceat all...thanks...