Having some idle and hesitation issues with my truck. Idle darts around at random times and truck has lots of hesitation in gear at half to full throttle causing it to buck some. I have parts for six liter tune up but haven't gotten into it yet. I have a code reader and got to try the first two readings but not the last one with it running. Couldn't go wot in the neighborhood. No codes with key on or stored codes. I disconnected the iac while running and the truck actually cut off. That normal? What should next step be? Codes while running? The smog pump was bypassed by previous owner.....can I remove the hose off the pump and the canister it goes to?

 

I'd do a thorough cleaning on the throttle body.