L5P new ecm doesnt work after writing the tume

after writing the tune to my new unlocked ecm it will not start the truck, cranks for a second then stops. I can clear the DTC's and it will try again for one second then the same just stops. I went through the ECM swap process but while my tune was being wrote I put the old ecm back in the truck so I could drive it while I waited. When the tune arrived I just put the new ecm back in then wrote the new program. Is my issue being that I should have started at step one again and done the ecm swap process once more before writing to the new ecm? I also had an issue with the VIN number not being listed nust all y's but i was able to fix that issue.

What tune are you trying to upload into the truck??

The tune came from tuners depot. The truck is running now but the check engine light is on and there are a bunch of fuel related DTC's. The support at tuners depot is terrible, I am trying to get them re check their tune.

tuner depot, without the "s" I believe there are two different sites with that being the only difference in the name

How are they able to sell delete tunes for an HPT device ? Something the rest don't know ? A secret back door ?

i can make a delete tune with hptuners all day every day.

Yes there are people that do it but EPA has driven it underground, since the EPA continues to go after anyone offering such defeats. Unless you get it from our friends to the north where they have no such issues.