running a boost gauge will do nothing to your car, if its a manual boost controller then that "shouldn't" really be run without an aftermarket ECU. u can still run it but the standard ecu still puts in the same air/fuel ratio for normal boost (14psi) even if u have it set at 16psi which makes it run lean. Theres topics for both of these *installing boost Gauge* and *effects of boost controller* just use the search funtion and u will find loads of info on it.