Stay away from Precision Mustang Performance. I had a car down from the Dallas area this past week that just never ran like it should. Issues found:
1. Knock sensor wiring harness was pinched between the bell housing and engine severing wires to one of the sensors. Fixed.
2. Transmission was 1.5 qts. low from a converter install.
3. Worst tune I have ever seen on a 2011+ 5.0.
These issues were resolved along with a few others. Car is now running and driving like it should with more to come. Next is removing the hot air intake.
A few pics of the issues: