I need some help solving some codes

[blue83ranger]

Truck is an '86 ranger 2.9 4x4 w/ a/c and converted from an A4LD to a C4. The codes i got are 21, 24, 18, and 33. Code 21 is because i didn't warm the truck up first so I'm going to ignore that one and code 24 is air temp sensor out of self test range, so does that mean the sensor is bad or did the engine need to be warmed up for that one too? Code 18 is spout open/erratic IDM, ECM, or Spout fault. So my question on that one is how do i fix it? About 3 years ago i replaced everything electric in/on the distributor so a bad pickup/TFI doesn't seem to likely. and code 33 is EGR not working properly, when i got the truck i cleaned all passages of the EGR and replaced the rusted out pipe from the exhaust. I can use a vac. gauge and the egr does work and the vac. lines are good. From what i can see there are only 2 electronic pieces that have anything to do with the EGR. So i guess my question is how do I test each one? One is a vac. line that goes to the tube coming from the exhaust and the other allows vac. to the EGR to open it, sorry i don't know the technical names for them. thanks for any help.