We warn against turbo-based applications for anything involving the air-intake system, including PCV valve and brake booster, just because turbo chargers can be very sensitive. However, these cleaners have certainly been used successfully in such applications, although the user assumes responsibility for “off-label” utilization. You might check some PT Cruiser and/or turbo forums and see how other owners have gone cleaning up excessive carbon. If you move forward with one of the B-12 Chemtool family of cleaners, please let us know which product you chose and what your results were. Either way, best of luck!