What are the symptoms of driving with a blocked exhaust pipe?

[LaAngela]

After the exhaust pipe is blocked, the following symptoms may occur while driving: 1. Poor acceleration: During long-distance driving, the blockage of the exhaust pipe causes poor exhaust flow, leading to reduced air intake and decreased engine power. This may result in unstable engine idling, weak acceleration, and a feeling of the car being sluggish. 2. Frequent forced downshifting of automatic transmission: The blockage of the exhaust pipe reduces engine power, prompting the driver to press the accelerator deeply to speed up, which fully opens the throttle. At this point, the car will control the automatic transmission to force a downshift based on the throttle's condition. 3. Slight backfiring during sudden acceleration: A blocked exhaust pipe causes some exhaust gases to remain in the cylinders, making the air-fuel mixture leaner and slowing the combustion speed. When the intake valve opens, the mixture is still burning, so it may backfire through the open intake valve into the intake manifold, causing a backfire phenomenon.