[200q20v] Question

[Chewy4000 at aol.com]

That bring up a question of mine.
My car about 2 yrs ago would go 1.8 sometimes 1.9 bar.
These days it only goes 1.5. I changed the Bpv since it would stall when I come to a sudden stop. After changing the valve there was no difference.

What else should I check to get the 1.8 or whatever its supposed to get at.

I also have the common gas leak from fittings or the pressure reg sypton, that maybe the cause of the car hesitating trought the gears.

TIA
Chewy