What are the consequences of a clogged catalytic converter?
2 Answers
The consequences of a clogged catalytic converter are: 1. The car experiences weak acceleration, with difficulty in increasing engine speed and vehicle speed. Restricted exhaust flow reduces intake air volume, leading to decreased engine power; 2. Automatic transmission vehicles frequently force downshifts. Exhaust blockage causes reduced engine power, prompting the driver to press the accelerator harder for more power output. This results in the throttle opening wide, and the ECU, based on the throttle opening state, controls the automatic transmission to force downshifts; 3. The engine exhibits slight backfire when accelerating sharply. When exhaust flow is restricted, some exhaust gases remain in the cylinders, causing backfire; 4. When the engine accelerates sharply or the throttle is suddenly released, a rattling sound can be heard from the exhaust pipe. This is often a symptom of a damaged catalytic converter, and a broken catalytic converter can easily cause engine exhaust blockage.
From the perspective of automotive mechanics, a clogged three-way catalytic converter directly interferes with the normal operation of the exhaust system. Once the catalytic converter is blocked, exhaust airflow is obstructed, causing a sharp increase in backpressure. This prevents the engine's exhaust gases from being discharged smoothly. Consequences include a significant drop in combustion efficiency, noticeably sluggish vehicle acceleration, and a feeling of dragging heavy loads when climbing hills. Fuel consumption will also spike sharply—normal city driving may increase from 10 liters per 100 km to over 13 liters. Another issue is excessive emissions: the catalytic converter is supposed to treat harmful gases like CO and NOx, but when clogged, it fails, resulting in thick black exhaust smoke. This not only causes severe pollution but also triggers the check engine light on the dashboard. If repairs are delayed, the catalytic converter may overheat, deform, or even melt, requiring a replacement that can cost thousands. I've seen many vehicles suffer damage to the entire exhaust system due to this issue, so I recommend regular maintenance—ideally inspecting every 50,000 km—and using high-quality fuel to reduce carbon buildup.
