Is it necessary to replace a faulty three-way catalytic converter?
2 Answers
It is necessary to replace a faulty three-way catalytic converter. Here are the relevant details: 1. Causes of failure: Generally, the causes of three-way catalytic converter failure include poor fuel quality, engine malfunctions, and reaching the designed lifespan. Lead and sulfur in fuel, as well as phosphorus and zinc in lubricating oil, can cause significant harm to the three-way catalytic converter, with lead being the most harmful. Engine misfires, excessively rich or lean air-fuel mixtures, and engine oil burning can also severely affect the catalytic converter. Once the designed lifespan is reached, replacement is the only option. 2. Consequences of failure: If the three-way catalytic converter fails and the oxygen content at both ends is the same, the oxygen sensor will send a signal to the electronic control unit indicating excessive oxygen levels. The unit will then interpret this as a lean mixture and increase fuel injection, resulting in an overly rich mixture and higher fuel consumption. If the catalytic converter is clogged, the oxygen sensor will detect insufficient oxygen in the exhaust, misinterpreting it as an overly rich mixture, and reduce fuel injection, leading to a lean mixture and symptoms like poor acceleration. Additionally, a malfunctioning three-way catalytic converter will cause carbon monoxide and hydrocarbon levels to exceed standards during vehicle inspections, resulting in failure to pass annual inspections and inability to obtain the vehicle inspection compliance sticker.
I've been driving for over twenty years, and a faulty catalytic converter doesn't always require replacement. The key lies in the severity of the issue: if it's a minor blockage or poisoning, a professional cleaning might do the trick, saving you a lot of money. However, if the catalytic substrate is cracked or completely failed, replacement is a must. Otherwise, the car will lack power, fuel consumption will skyrocket, and it will pollute the environment. I once experienced it firsthand—when the converter failed and wasn't addressed promptly, the engine light stayed on, the car failed the annual inspection, and the repair cost even more. My advice is to check for symptoms as soon as possible; if there's abnormal exhaust color or a pungent smell, don't delay—safety comes first. Regular maintenance of the exhaust system can prevent issues, such as avoiding prolonged low-speed driving. The final decision depends on the diagnostic results—don’t blindly replace or ignore it. It never hurts to consult multiple repair shops to compare solutions.
