We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

Absolutely. Even if you clear customs through gray channels, local commercial insurance companies will refuse to cover third-party liability insurance due to the vehicle not complying with national traffic laws; additionally, the vehicle will definitely fail the annual safety inspection at the local DMV.

Yes. For hybrid vehicles, technicians will conduct forced switching tests between EV (electric) and HEV (hybrid) modes, focusing on the sensation of clutch engagement and reading the hybrid system's specific fault codes to ensure the complex dual power system operates correctly.