I have a 91 ford f150 5.0l truck with a high then low idle. I also misses badly at idle most of the time and when I give it gas going down the road it misses bad. The engine vibrates a lot. I have retrieved the DTC's KOEO= DTC 23 TPS out of range...DTC 12....DTC 34....I have no Idea what to look for other than unhooked sensors or bad sensors I have replaced the TPS IAC cap rotor checked the timing, Looked for air leaks even used propane, Made sure the spark plugs were not fouled. I have no idea what it means when my tps is out of range. KOER= DTC 23 DTC 13 DTC 77 DTC 12....Help would be great...and I have looked for pages to help me diagnose these codes and havent seen any I have found numerous pages of the definitions though but that does not help me find the problem.....I have erased all the codes with my scanner and these are what showed up after the erase.