pcv valve ?

does really help the engine run better with a new pcv valve ?

It depends on the mileage on the car and age of the PCV valve. Replacing it should be done as routine maintenance. Depending on which engine you have in your GP, a bad PCV valve can cause engine vacuum related problems, affect MAP, and possibly trigger emissions related odb-ii DTC error codes like EGR flow test problems.

Yep, as Bnaylor stated, the possible hassles that a clogged PCV can cause are not worth saving the $3 they cost. Considering they take less than 5 minutes to replace, change it.

I just replaced mine in my 2000 GTP after 135,000 miles. It is my DD that I drive 80+ miles a day. I monitor my gas mileage pretty carefully, (what else is there to do on CA freeways?), and it seems as though I picked up about 1 MPG going from an average of 23.5 to 24.5-25 MPG.

The PVC valve did not seem clogged when I pulled it out but I feel the new one probably offers benefits. Plus it is only $3.00 and 5 minutes of time to change it.

I had changed the fuel filter a week earlier. The original was totally clogged and believe that to be an important maintenance item as well that may have contributed to the gain.