Most tuners disable the necessary drive cycle tests that many states with emissions inspections require.
In PA, for example, 1996 and later OBDII vehicles are no longer "sniffed" at the tailpipe. Instead, the system checks the emissions related drive cycle monitors for successful completion.
Those monitors check things at various operating conditions and are actually a good indication of a healthy emissions system.
The problem you will have is that first of course you need to return your truck to stock. Secondly, those monitors must have time to complete and you'll need to drive around a bit before they do.
Last, in order to KNOW they've completed you need a scanner which indicates their status. Paul has one like my Equus 3110 that has the 3 LED's to indicate status. A green LED means ready for inspection verification.
In addition, most have icons or a scrollable list of tests that have not yet completed, or have failed.
The pesky one for me was the vapor recovery system check. That took awhile to complete on my truck. It was failing until I cleaned out the valve in the charcoal cannister which probably got screwed up going through deep water on mine.