The maintenance technicians arrived at the site and found that the 0R-0471 injectors were installed incorrectly: the sealing gasket was reversed, and the fixing bolts were tightened too tightly, resulting in damage to the sealing gasket and oil leakage; at the same time, the incorrect installation angle of the injectors led to uneven injection, causing engine vibration. In addition, the site personnel did not clean the installation interface before installation, and there were impurities on the interface, which also affected the sealing performance.