Diesel Bombers - 6.4 Backfires

Guys I need help. We've got a customer that did a DPF Delete, Edge Racing Module, S/B Intake. Customer says about every 100 to 300 miles while cruising down the road the truck will backfire. We took everything off the truck except the S/B and sent him to Ford. Ford said everything is good to go. We had customer drive vehicle bone stock for some time but it still does it. Then Ford said it was the intake allowing to much air to the engine, so we took it off. Still does it. Ford then updated all the modules, he drove it for awhile without any problems so we installed everything back on the vehicle and low and behold it's doing it again. We updated the Edge same issue. Edge says they've never heard of it. We installed SCT still same thing. Any ideas??????