1.6 tdci intermittant boost drop

[bigmick1981]

Hello all got a grand cmax 1.6tdci 115 

Noticed sometimes when driving along the car feels sluggish , so plugged in a obd scanner and when driving no issues it will boost to a steady 22 psi . When the car looses some performance it will only boost to 18 psi , it's usually happening after a gear change but has happened a couple of times at early stage of acceleration . Now for the strange part if it drops to giving me a solid 18 psi it doesn't mater if I back of the throttle and foot down again or push through it will only give a steady 18 psi but if i quickly down and up with the clutch it will give me back the boost to 22 psi . 

 

dpf not blocked Max difference is around 17 kpa, had the diesel filter changed with no difference,veins in turbo move freely and egr request to fault ratio never out by more than at max 2% but this is at crossover of on and off. 

 

Any ideas folks ? 

[Geordiedave68]

Does it matter if its hot or cold.?

[bigmick1981]

No its always there hot or cold but if in say fourth and it's boosting to 22 psi then on off throttle it stays good but once you change gear it's anybody guess if it will come back as 22 psi or drop to 18 psi untill clutch operated or once changed gear it might boost to 22 psi for a second then die straight down to 18 psi and hold that till clutch pushed again. It's at 22 psi more than 18 psi and can't see it being clutch switch related more load related but I'm just guessing 

[bigmick1981]

 Seems like it's going up a hill from thinking about it sets it up the most