ok i have a 99 expy 5.4L. i believe i have the 4r100 tranny. a lil while back my OD off light would flash a few times then stop and i didnt notice anything wrong with the way she was driving. about 3-4 months ago it was a constant flickering and shifted hard from 1st to 2nd and 2nd to 3rd. but only up shifts never an issue down shifting. so first thing i did was change tranny fluid and filter, which looked clean, cause it was due anyway and ran a scan on her. came up with a p0708. so i changed the tranny range sensor but code never went away and shifting never changed still banged going into those gears. right after that i got into and accident with my triaxle so was unable to further work on my truck for i do not trust many people to do my own work. so i just let the problem go and continued driving it. today getting off the highway came to a stop, light turns green and rpms jump up but truck barely moves until rpms get over 3000 and then speed will build. thought i blew my tranny, but i came to a stop again and shift it down to 1st and manually shifted 1st, 2nd and then into drive. after that i noticed it would not shift from 3rd to 4th or 3rd to 2nd. so its stuck in 3rd. i got home checked no blown fuses so through the scan on her and got these codes, P0705, P0708- both are for the tranny range sensor, P0734-torque converter clutch solenoid, P0750- shift solenoid A, P0755- shift solenoid B, P1747- electronic pressure control solenoid. can all these things really go bad at the same time or is one or two the cause of the rest? i also got all 4 O2 sensor codes i figured due to the struggle of the engine to move. i found the torque converter clutch solenoid and shift interlock solenoid can cause these problems. the cheapest i found a used tranny was for $500, i can get the torque clutch solenoid and shift interlock solenoid for under $70, i rather replace the stuff that went bad rather than the whole tranny. what else would i need to replace? should i start with the clutch solenoid and interlock solenoid, plus what other parts while im already dropping the tranny pan and having my hands in there? any help would be great, again seems like the parts would be cheaper than replacing the tranny with a used one and possibly having the same issue or worse.