STAGE 0 - before tuning Here is a summary of recommendations that should be followed before any modification - increase - performance. These recommendations can safely achieve the performance that is required. However, these recommendations can also serve as a guide for extended maintenance to get the engine back to what it has lost in years of operation. These recommendations not only restore original performance, but also extend engine life. engine oil change, oil leak check oil filter replacement air filter replacement fuel filter replacement turbocharger check / check…