Why does the Audi A6L shake severely when reversing?

[Peterson]

The reasons for severe shaking when reversing in an Audi A6L are as follows: Severe engine carbon buildup: The most common cause of car shaking is a dirty throttle body or excessive carbon deposits in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector can be largely absorbed by the carbon deposits. Engine misfire: An engine misfire mainly refers to one or more cylinders not functioning properly. This manifests as noticeable intermittent exhaust gas flow, severe shaking of the exhaust pipe, and a clear sensation of engine vibration, sometimes accompanied by a sputtering sound. This is often related to ignition coil failure. Fluctuating air-fuel mixture in the engine: This causes idle shaking after a cold start. The lower the temperature, the more fuel is required for a cold start, and the presence of carbon deposits will significantly affect whether the cold start proceeds smoothly.