I am having some sort of issue with vaccuum and am sure someone here can help me with this. So when my car is idling and I step on the breaks it tries to die almost every time. Only time it doesnt is at the end of a race when im breaking to get off the track. I have !egr, !air and am prefty sure the rest of the vaccuum lines are hooked up correctly. Anyone?? Just posted about opti issues... I understand this could be the other explanation. Thanks

 

A badly leaking brake booster can cause this.

 

+1. They can and do fail internally. Personal experience. Definitely rule out the check valve first tho.