Can't win with new injectors in ISC

[hookliftpete]

So far this year, determined two injectors were bad, replaced those, replaced DPF and did the egr tuneup a second time since owning this truck. These changes helped for about two months, and put me back to about 10 hours between regens. Seemed like things were moving in the right direction, but this week I'm down to about 3-5 hours between regens, right about where I was before the 2 new injectors and new DPF....This is my second year in business with this truck. I do not have much more wiggle room with the bank and investors in keeping things paid up. I suppose I need to look at the de-mandate route. Where do I start? Thanks in advance for help, I'm needing all I can get at this point, before the season gets too busy.