8) Check catalytic converter and turbo module

Catalytic converters can influence the charging through modified exhaust gas counterpressure. This is normally detectable through melting or combustion in the honeycomb structure. Annealing colors on the outside of the catalytic converter can also indicate this type of damage. Damages to the exhaust turbocharger are normally visible through, e.g. broken turbine wheel, stuck turbine shaft or oil leakage. For oil leakage, the catalytic converter must absolutely be checked for subsequent damage.