One or more of the following may be evident:
? Engine has restricted performance;
? Engine runs rough;
? Engine exhibits poor starting; and/or
? Engine MIL (Malfunction Indicator Lamp) illuminated with DTC (Diagnostic Trouble Code) P0300, P0301, P0302, P0303, P0304, and/or P1315 stored in the Powertrain Control Module (PCM).