Occasional Suggish throttle

Over the last week I am noticing when I try to accelerate it dogs down then suddenly off it goes. It does this whether the a/c is on or off and I have no check engine light on. It's a 1994 limited 4x4 with 168k miles. I hqave replaced teh fuel pump, plugs, maf, injectors, plugs, wires, egr, AIR cleaned and pressure tested the air intake tube with in the last 1000 miles. I did have a code cleared about 2 months ago for l"eft bank lean condition"

Thanks in advance for any ideas, Jeff

try the throttle position sensor.