For a correct EVO4 installation it is important to follow some simple rules. First: carry out CAN, serial or OBDII connection only AFTER performing the logger configuration with Race Studio 2.
For a correct working of the integrated three-axial accelerometer, EVO4 is to be placed in a central position of the car (ideally where the vehicle barycentre is located).
GPS antenna is not to be positioned under metal objects, which would greatly reduce the satellite signal quality.
It is also important to avoid tightening too much the nut when fixing the connectors.
Finally, avoid to install the product with tense cables.