This Preliminary Information communication provides information to the technician about vehicles that may be running rough with a Malfunction Indicator Lamp on. The technician may find Diagnostic Trouble Code P0300 set. The technician will need to perform engine compression and leakage Testing in Service Information. If excessive leakage to the crankcase is isolated, the technicain is directed to check the condition of all cylinder walls.If the cylinder wall surface has not been damaged, the technician is directed to replace all four pistons.
