just to update on this:
I followed the link above which suggested to to remove the oil cap for a very brief moment as you don't want to screw up the pressure ..
I did this exactly as suggested, lifted the lid very briefly. and found the engine was behaving as expected ie revs increasing.. i gathered fro mthis that the pv is fine...
However shortly after this, when I started driving again, Engine emissions lights had come on and has been on since(3 days)....
I have no idea if the two are related...just wanted to ask if this could possible....
cheers