A hole in a catalytic converter usually causes a louder exhaust, hissing or ticking from underneath the vehicle, visible soot around the damaged area, and a stronger exhaust smell. A large leak can also trigger a check engine light, affect emissions readings, and allow dangerous exhaust gases to collect near or inside the passenger compartment….

A dirty or contaminated catalytic converter may cause weak acceleration, reduced engine power, poor fuel economy, hard starting, unusual exhaust smells, excessive heat, a check-engine light, or stalling. Symptoms become more severe if deposits or damaged catalyst material begin restricting exhaust flow through the converter. The term “dirty converter” can describe more than ordinary surface…

A catalytic converter that is starting to fail may trigger a Check Engine light, reduce acceleration, create a sulfur or rotten-egg exhaust smell, lower fuel economy, rattle internally, run unusually hot, or make the engine hard to start. A badly restricted converter may eventually cause stalling or prevent the engine from running. These symptoms do…

An overheated catalytic converter may produce extreme underbody heat, a hot or burning smell, weak acceleration, rough running, dark heat discoloration, and in severe cases a converter shell that glows red. The converter is often being overheated by an engine problem such as a misfire or overly rich fuel mixture rather than by a fault…

Common signs of a failing catalytic converter include a check engine light, sluggish acceleration, reduced power at higher RPM, rattling underneath the vehicle, a sulfur-like exhaust smell, excess exhaust heat, poor fuel economy, and failed emissions testing. A clogged converter may also cause hard starting or stalling because exhaust gases cannot escape freely. The symptoms…

Most catalytic converter replacements take about 1–3 hours of hands-on shop labor. A simple direct-fit converter can sometimes be replaced in around an hour, while welded units, manifold-mounted converters, multiple-converter systems, rusted hardware, or difficult access can stretch the job to 3–5 hours or longer. The amount of time your car stays at the repair…

A catalytic converter commonly reaches several hundred degrees Fahrenheit during normal driving and can approach 1,000–1,200°F during heavy engine load. Internal temperatures can rise far higher during a severe misfire or rich fuel condition, and extreme heat can damage or melt the catalyst substrate. Those numbers need context because converter temperature changes with engine load,…

Inside a typical gasoline catalytic converter is a heat-resistant honeycomb core coated with a porous washcoat and tiny amounts of catalyst metals. The core sits inside a steel shell and is held by a cushioning mat. Exhaust flows through thousands of small passages where the coated surfaces convert carbon monoxide, hydrocarbons, and nitrogen oxides into…

Most automotive catalytic converters combine a stainless-steel outer shell, a ceramic or metallic honeycomb core, a heat-resistant washcoat, and tiny amounts of catalyst metals. Platinum, palladium, and rhodium are the best-known metals inside, but they form only a thin catalytic layer rather than the bulk of the converter. That distinction matters because the phrase “precious…