I assume your using the off the shelf map from cobb for the vf-34? How much boost are you seeing. Depending on the DP you have the vf-34 can tend to be a creepy turbo if it doesnt have a PnP wastegate. I get a tiny bit of creep with the cooler weather. My tuner also gave me a map that will lower my WG cycles to limit the boost I run above 6k.