This is a really old post and I'am only making a comment here because there seems to be very little discussion on the Envalve.
I actually put one of these on a Chrysler 4 cylinder, 2.5 liter back in the early 2000's when the car had about 200,000 miles on the engine and it was blowing oil into the air filter housing, esentially ruining the air filter and making a big mess. The Envalve solved that problem and I pretty much forgot about having that thing in there. This year, I had to re-seal the valve cover and when I pulled the valve cover off, I was astonished to see that it was pretty clean. The engine now has about 320,000 miles on it.
I'm thinking of adapting one of these to a 98 Caravan with 316,000 miles on it. I don't know how it will work out with the newer engine computers. Essentially, all discussion has ceased on the Envalve and the few out there call it total [censored]. The inventer has passed away (I made an inquiry through an old phone number to Chandler, AZ and talked to the wife). The unit is still sold on E-Bay.
I'm one speaking from over 10 years experience that this device really helps with blowby. I have no idea about emission reduction, gas savings, and any other claims. All I know is that it is a simple vacuum regulator that keeps about 4 inches of vacuum in the crankcase and uses the volume of the oil pan sort of as a vacuum canister. Is it crazy expensive? Yes, I would say so, but with no mass production and todays labor costs I can see why.
Once I get one of these in the 98, 2.4 Caravan, I'll report back. The big problem today is trying to get adapters to interface the unit to the port/hose size. For my original purchase, the inventor made adapters on his lathe and sent me one at no charge.
