CM870 High Pyro/Low Boost intermittent under load

[Bengy88]

I’ve seen what rawze is saying cause exactly your issue with a clogged air filter and a damaged turbo…. Also I wonder could your egr valve be opening just enough to loose boost? Is your boost gauge mechanical or electrical? We’ve all seen false boost and egr pressure readings cause issues like this as well. There are really a lot of factors that can play into this. The black smoke points away from a derate. Black smoke comes from a boost air issue.