The Tune will not cause that issue.

It's likely a loose wire somewhere. Check the fuse block connection, the PCM connection, check the grounds at the back of the block.

 

I have checked grounds, new battery, have not checked ecm. Its just like someone turns the switch off. I don't lose the radio memory like a power loss, the engine revs like the trans is neutral, it makes that cycle, then its normal

 

Could be the ignition switch.

 

i have mine supercharged and with factory magnason tune it was as advertised.. 100 hp and 120 lbs. Basically stock engine. So that put me at 350+ rwhp and 400+ rwlb. I got a Westers tune and it has a big seat of the pants feel but i havent been back to have it dyno'd yet. it does pull my 26 ft trailer alot better.

 

Before you switch to the smaller pulley you should verify what fuel system is in the truck.