99 k2500 won't shift out of Drive

[dnbuggy]

99 K2500 7.4L Truck lacks power when put under load and has several lean condition codes. Truck also won't shift into other gears. Just stays in drive (I do have reverse). Fuel pressure is 52 at 2000 rpm. The truck will rev up to 4-5K RPM's in Park and Neutral, but will not go above 2200 RPM's when driving.
CODES
P0131
P0137
P0151
P0157
P0171
P0174

I replaced the fuel filter and no change. I also unhooked the battery and left off overnight to reset codes and possible limp mode. No change, but codes are now gone. What would keep me from shifting into 1, 2, and 3rd gear, but would let me drive in D and R? There is also still a small misfire at idle.

 

[Schurkey]

You don't have any problem moving the shift lever from P-R-N-OD-D-2-1...right? YOU can shift the thing just fine. Problem is that the only forward gear you get is 3rd...right?


Is 3rd gear the default for limp-home mode?
What is the spec for fuel pressure? '97 is 56--62 with the engine off (no vacuum to regulator.)
How old are the O2 sensors?
How old are the usual "tune-up" parts--cap, rotor, plug wires, plugs, air filter, etc.


Connect a scan tool, check for ALL codes--engine, trans, ABS, instrument cluster, etc. Current codes, history codes, and pending codes. Disconnecting the battery doesn't clear codes on OBD2. Won't re-set limp mode, either, if the fault is still present when the battery is re-connected.

Please post the code definitions as well as the code numbers.

IF the computer detects misfire, it'll also lock-out the torque converter clutch.