[aknovaman]

Bad advise above about unplugging the MAF. That only works if the MAF is a 3 wire and a separate IAT sensor.

The truck will run like poop if you unplug the MAF. The IAT is part of the 5 wire MAF and with it unplugged, the PCM will see -40 degree air and change the air mixture and throw all the fueling even further off.

Don't do band aid fixes or experiments, get your tuner to connect his datalogger and see some real data and determine whats the real cause. He can disable the MAF and put the truck in SD to eval if the MAF is broke or if your intake MAF table or positioning needs adjusted or if the 02 sensors are cycling to produce the necessary voltage levels. That's coming from over 17 years of tuning experience.