Series 60 erratic performance

If you have a air compressor inlet line that feeds off the boost side of the air box or intake inspect the rubber line for breaks or run the engine and listen for rushing air sound. The engine brake might be a separate issue but I think I noticed a weaker engine brake when my inlet line blew, some how maybe there is a connection with turbo propeller speed and thus the broken air line might have cause difference in engine braking.