In the automotive aftermarket, three-way catalytic converter failures are a frequent challenge for automakers and repairers. Failures not only cause vehicles to exceed emission standards and suffer power degradation but also easily lead to customer complaints and rework, increasing after-sales costs. As a foreign trade supplier specializing in this field, we have summarized four core types of failures based on global service experience, analyzed their causes and identification methods, and provided full-chain prevention solutions to help partners reduce costs and improve efficiency at the source, and enhance customer satisfaction.
I. Four Common Failures: Causes and Identification Points
Failure 1: Catalyst Clogging (Most Frequent Failure)
Causes: This is the most frequent failure, with three core triggers: 1) Poor fuel quality—fuel containing impurities such as sulfur and phosphorus generates solid deposits after combustion, clogging the channels of the honeycomb carrier; 2) Engine oil burning—oil additives form carbon deposits at high temperatures, hindering exhaust gas circulation; 3) Catalyst aging—loss of active components combined with particulate deposition exacerbates clogging.
Identification: Judged by vehicle operating conditions, typical symptoms include: decreased power and weak acceleration (especially obvious at high speeds); fuel consumption increased by 10%-20%; abnormal exhaust noise; OBD alarm triggered and fault light illuminated in some models.
Failure 2: Catalyst Invalidation (Substandard Purification Performance)
Causes: Catalyst invalidation is the main cause of excessive emissions, resulting from two factors: 1) Improper operating conditions, such as long-term short-distance driving, frequent cold starts, or use in harsh environments, accelerating the attenuation of active components; 2) External damage, such as undercarriage impact, improper installation leading to shell deformation and poor sealing, affecting purification efficiency.
Identification: The OBD system will alarm “excessive emissions”; professional testing can confirm excessive CO, HC, and NOx emissions; some models are accompanied by unstable idling and vibration.
Failure 3: Catalyst Shell Damage/Carrier Fracture
Causes: Mostly caused by external forces, common scenarios include: damage to the shell due to collision with road debris during driving; carrier fracture caused by improper maintenance operations (collision, loose fixation); carrier cracking due to thermal expansion and contraction when the high-temperature catalyst is sprayed with cold water.
Identification: Check the undercarriage catalyst—obvious impact marks or deformation on the shell indicate initial judgment; a “rattle” noise from the exhaust pipe during driving, which seriously affects exhaust and leads to power loss.
Failure 4: Catalyst Interface Air Leakage
Causes: Interface air leakage indirectly causes power degradation, main reasons include: aging and damage of flange gaskets; loose vibration due to insufficient tightening of mounting bolts; weld cracking caused by shell welding defects.
Identification: After the vehicle starts, a “hissing” air leakage sound near the interface; slight power loss and increased exhaust odor in some models.
II. Full-Chain Solutions: Cost Reduction at the Source
For the four failures, provide full-cycle support from three dimensions—”front-end selection, mid-term use, and after-sales service”—to reduce repair probability:
1. Front-End Selection: Match Suitable Products to Avoid Inherent Risks
Front-End Selection: Assist customers in matching products according to vehicle models and scenarios, such as recommending high sulfur-resistant and carbon deposit-resistant models for markets with poor fuel quality, and providing thickened protective models for bumpy road conditions; provide supporting installation manuals to clarify details and avoid installation failures.
2. Mid-Term Use: Issue Maintenance Guides to Standardize Usage Habits
Mid-Term Use: Issue “Maintenance Guides” with core recommendations: use high-quality fuel; regularly inspect and maintain the engine; avoid long-term short-distance driving, and conduct high-speed driving for more than 30 minutes once a week; avoid deep puddles on rainy days.
3. After-Sales Service: Optimize Response to Provide Precise Support
After-Sales Service: Establish a rapid response mechanism to provide “remote diagnosis + on-site support”; provide supporting original maintenance parts; conduct regular inspections for long-term customers to identify potential hazards in advance.
III. Conclusion: Professional Support Empowers Partners
Most after-sales failures of catalysts are related to usage, adaptation, and installation, not purely quality issues. We not only provide high-quality compliant products but also focus on technical empowerment. In the future, we will continue to release maintenance knowledge and solutions. For the “Catalyst Fault Diagnosis Flow Chart” or customized training materials, please contact our dedicated team.
Russian 
English