What Are the Consequences of an Aging Three-Way Catalytic Converter?
3 Answers
The consequences of an aging three-way catalytic converter are as follows: The aging of the oxygen storage capacity of the three-way catalytic converter causes it to fail, preventing the incomplete oxides from undergoing chemical reactions with oxygen inside it to form complete oxides. The resulting consequence is failure to meet emission standards. Additionally, fuel injection correction becomes inaccurate. Extended information: 1. Three-Way Catalytic Converter: The three-way catalytic converter is the most important external purification device installed in a car's exhaust system. It converts harmful gases such as CO (carbon monoxide), HC (hydrocarbons), and NOx (nitrogen oxides) emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. Because this catalytic converter can simultaneously convert the three main harmful substances in exhaust gases into harmless substances, it is called a three-way converter. 2. Working Principle of the Three-Way Catalytic Converter: When high-temperature vehicle exhaust passes through the purification device, the purifying agent in the three-way catalytic converter enhances the activity of CO, HC, and NOx gases, promoting certain oxidation-reduction chemical reactions. Among these, CO oxidizes at high temperatures into colorless, non-toxic carbon dioxide gas; HC compounds oxidize at high temperatures into water (H2O) and carbon dioxide; and NOx is reduced into nitrogen and oxygen. The three harmful gases are transformed into harmless gases, thereby purifying the vehicle exhaust.
Last time my car failed the annual inspection, the mechanic said the catalytic converter was worn out. This part is located in the exhaust pipe and specifically treats exhaust gases. When it fails, pollutants like carbon monoxide and nitrogen oxides exceed emission standards, not only polluting the air but also easily triggering the engine warning light. I specifically researched that severely aged converters can even clog the exhaust system, making the engine feel like it's being strangled - you can floor the accelerator but the car won't move properly, while fuel consumption increases by 20-30%. What's worse, the car will definitely fail the annual inspection, and some cities even impose fines. Replacing it with an OEM part costs several thousand yuan, which really hurts the wallet.
I've been repairing cars for over 20 years and have seen countless cases of aging catalytic converters. The most obvious symptom is particularly foul exhaust fumes - you can even smell the acidic odor standing behind the vehicle. The engine warning light comes on, and diagnostic scans show multiple post-oxygen sensor error codes. Increased exhaust backpressure makes the car sluggish during acceleration while fuel consumption skyrockets. Just last week, an old Camry came in with its catalytic converter completely shattered into pieces. The debris got sucked back into the engine and scored the cylinder walls, ultimately requiring an $8,000+ overhaul. So whenever you notice abnormal exhaust noises or power loss, get that catalytic converter checked immediately.
