Hi

Ive just purchased a k plate turbo with 47000miles on the clock. The first two weeks of ownership have been great but I have this loss of power in the mid range to top end. If you floor it it picks up well then suddenly looses it's go and then comes back but not as well as before. This problem is less noticeable when running SUL than NUL. Why is this.
Hope someone can help

 

Is it a sudden drop-off in power?

If so, it could be overboosting. I am no expert, but I think there's something in the FAQ about it. I think there's an easy fix too. The faq is at