Truck shutters and shakes

My truck is the XLT model. It will like shutter and shake, say like when I cruising along at any speed and I step on the gas pedal to speed up I get this shimmy/shake. It feels like your driving over those rumble sticks on some highways or if your driving a stick shift and you try to start out in like four gear it will also do while cruising along and start up a hill/incline or grade change, if I immediately let off the gas it will stop or I can accelerate through it. The check engine light has been coming on and off intermittently throwing a DTC 181, fuel system at rich adaptive limit at part throttle, system lean. I recently replaced plugs, plug cables, air filter, mass air flow sensor, tested EGR it was fine, replaced O2 sensor. Checked all vacuum lines, replaced vacuum canister, checked fuel pressure it was within spec, replace fuel pressure regulator. Recently replaced tie rod ends, u-joints, front shocks, radius arm bushings upper and lower ball joints, had front end aligned new tires all around/balanced, replaced front and rear wheel bearings, new radiator, new water pump, thermostat, front engine cover gasket, new alternator, new starter and new battery. It even has brand new windshield wipers and a new fuel filter.