Swirl valve actuator Torx Size

[456eec]

Hi,
I'm just working up the courage to remove my swirl valve actuator to try to sort out a chronic EGR/ASP + limp mode fault that comes up in my 2006 2.2 C5 estate. Highway speeds only and often going up a slight hill. Has spent 8 weeks at various dealers and repairers who have replaced and done everything but havent fixed it. The swirl valve has never been mentioned and even the Citroen dealer admitted they didn't know much about the 2.2 motor as it's rare in Australia. I finally decided I'm more likely to be able to fix it myself.
I've trawled the forums and worked out that it needs to ba accessed from below. There is a youtube video of a French guy using a long extension to access the 4 Torx screws from above and through all the pipes and things.
To make it easy for myself I'm going to get a long extension but would like to know the Torx size of the bolts before I start. If anyone knows I would be appreciative.
Also how does the valve actually come apart to cgheck the diaphragm. Any advice appreciated.

Edit- I just had another look and actually found that it is a T20.

[horsedentist]

I wouldn't bother taking it apart they are so cheap better to just put a new one in. Sometimes you can tell if it is a goner by getting someone to slowly rev the car while you watch the actuator it should snap open around 2100 rpm and stay open for a while and then shut in a controlled manner. Mine was snapping open then snapping shut there was not enough vac to hold it. Another thing you can do to test it is take the top pipe off of the electro valve put a plug in the vac pipe and take it for a spin if it doesn't go into limp the actuator is the problem.

[dawsy 22]

I would first check the rubber hose which connects to the actuator mine was split and the actuator was fine,I did change the actuator only because i had already purchased it. Horsedentist i have read other threads on here that state that the actuator should open upon engine start up,mine seems the same as yours,that is when the engine is not running it is in one position,when you start up it stays in that position until you reach 2,100 rpm and then it changes position