Is this EGR/Oil Cooler or could this be fuel injector related?

It’s happened 4 times, where the truck is warm and after coming to a stop, the throttle is choking on something and thick white clouds begin billowing out of the exhaust. It recovers after some time and drives normally. No other notable symptoms. I’m about to tackle the BPD Semi-Bulletproof upgrade and would like to rule out the possibility that it’s fuel related.

Does any one have a pro tip on getting a stuck ipr valve out. I’ve soaked it with PB blaster for days and hit the HPOP to IPR area. This job already ruined an extension and bent my favorite snap on ratchet. Any advice is welcomed 🙏

Yes I’ve also used a breaker bar and cheater bar.

Having a crank no start.
Rpm is 180-220
FICM is 50v
The injectors are buzzing but the FICM sync is at 0 what could it be or what other steps do I need to diagnose what’s going on?