Originally Posted by
DmaxMaverick
The vibration is normal. ECM boost control is not on/off, but is modulated and will allow wastegate opening at a gradual rate. 17" is a little high, but within the margin of error. 15" is ideal at sea level at any "full closed" RPM, with 11" the minimum. Less than ideal variations could be a matter of a well seasoned solenoid, or aftermarket programming adjustments. If you have an aftermarket power program, it wouldn't be unusual to have increased wastegate actuator vacuum, as a means to compensate for increased exhaust back pressure against the wastegate.