4l80e shifting

I'm having shifting problems during hard acceleration from a start and when
tring to accelerate when already at a speed when the transmission downshifts.
The truck is a 2002 chevy silverado 2500HD with a 6L and 4l80e. Accelerating
slowly from a stop it shifts fine . Accelerating fast it won't shift gears . watching
on the computer it never is not being told to shift by the pcm. During this, all
that's required to make it shift is to lightly let off the gas then the pcm tells it to
shift. I think its the engine and pcm. No codes on anything, but I have two Chevy
extended vans one with 4.8L and one with 5.7 L both will blow the doors off this
truck with 6L ENGINE.  it doesn't over rev seems to go to 3500RPM then just
kind of sit there and nevershift. Same happens when tring to pass anything. The
computer downshifts but no go. Even at a speed if you try to accelerate without
causing downshift still is sluggish compared to the vans. Creeps slowly up .
worse around 50MPH up to 70 and 80MPH is top end speed with RPM max
about 3500RPM. I think its an engine issue nothing with the transmission. The
PCM is limiting the truck due to some issue, however there no codes being set.
My guess at the moment is catalytic converters. Any other thoughts or things to
check. All O2, TPS,mass airflow look good .