01 Silverado 1500 ( limp mode )
 

Trying to figure out why my truck is in limp mode.. some days it goes into over drive while doing 45 + but most days .. while driving on the road or freeway .. it feels like its in 3rd or 2nd because im doing 75 at 3k rpms.. an i let the gas off an bogs down really quickly an loses power than when i step on it again.. it takes awhile to climb back up to 75.. Recently changed all spark plugs back to AC delco .. an fixed a check valve on drive side bank 1 ..
Still acting up .. sometimes it feels like it slips gears an there is a delay in shifting .. not very consistent tho ..
No check engine light or soft codes .. I pulled the battery for about 12 hours to see if it would reset.. still was in limp mode when i drove tested it ..

Any suggestions ? Solenoids ? Thermostat or some kind of electronic?

( Side note .. if i drive for to long at 2500 - 3000k rpms i get a trans fluid hot light an i have to slow down to about 50 an keep it at 2k rpms or lower or ill get a red light saying engine hot an than a bunch of steam comes out of the engine and hood .. ) 133768 miles .. 2 tranny flushes in past 2 years..

trans fluid full? is your coolant full since it seems to be overheating and overflowing

Yes, both of those are full .. I've checked for leaks but its all okay.. its really weird..some days it drives fine an goes into over drive where other days its in limp mode..

I'd say you clearly have a tans issue of some sort, might need to have a trans shop diagnose it.

Could just be a bad sensor on your tranny. My cousin got stuck one time and when they pulled it out they knocked it off and it did the same exact thing as you're describing