Sometimes my GT2 pulls .7 or .8 instead of .9 Is that normal or is it a bad DV? Is there a way to test it? What happens when they fail? How long and hard are they to replace? Where else are the common intake hose leaks? The car has 3500mi on it. Thanks for the help. carl

 

What gear are you pulling for the comparisons?
Try it in 4 or 5, on a slight uphill grade, results should be repeatable. Anyway, DVs
are simple by design, and not prone to failure as such, but one sticking open should be easy to find, take it off and look at it.