Five FAQs about this critical exhaust component, turning off check engine lights and passing emissions tests

HOLLY, Mich., Sept. 10, 2025 (GLOBE NEWSWIRE) -- Under the Clean Air Act, catalytic converters have been mandatory for all gas-powered passenger vehicles sold in America since 1975. But most vehicle owners don’t give the CAT a second thought until something goes wrong. Here are five frequently asked questions about catalytic converters from the experts at leading automotive additive manufacturer Rislone.

1. What does the catalytic converter do? As exhaust passes through the catalytic converter, it converts harmful gases — carbon monoxide, hydrocarbons, and nitrogen oxides — into harmless carbon dioxide, nitrogen, and water vapor.
2. What are common catalytic converter problems? The catalytic converter is part of the exhaust system located under the vehicle, making it susceptible to physical damage from road debris, potholes, curbs, etc. Engine misfires or injector issues can cause carbon build-up and blockages. Contamination from oil or coolant leaking into the exhaust can coat the converter’s internal components.
3. Why do catalytic converters get stolen? Catalytic converters are the most frequently stolen car part in the U.S.A. because they contain precious metals such as platinum, palladium and rhodium, plus they are located outside the vehicle. Many can be removed with a saw in a minute or less. Thieves tend to target SUVs and trucks because their higher ground clearance makes them easier to slide under. To protect against CAT burglars, consider adding an anti-theft device and/or a car alarm that detects vibration, engraving the catalytic converter, and taking care when choosing a parking spot.
4. How do I know if something is wrong with my car’s catalytic converter? The vehicle will give you many signs that the catalytic converter is going bad. The most obvious is the check engine light or malfunction indicator lamp (MIL) turning on. Common OBD-II codes are P0420, P0430 and related. Many people notice a rotten egg smell coming from the exhaust or a rattling sound when driving. A vehicle with a bad CAT will fail emissions testing, its fuel economy will drop, and it may not accelerate smoothly. A plugged catalytic converter may also reduce power, performance and even cause engine overheating.
5. How should I take care of my catalytic converter? Follow the maintenance recommendations for your vehicle. Improper maintenance, as well as using poor-quality fuel and regularly driving only short distances, can contribute to catalytic converter problems. Never ignore the check engine light. Continuing to drive with the check engine light on can make the problem worse. Clean the exhaust, emissions and fuel system every 5,000 miles. Rislone Cat Complete^® Fuel, Exhaust & Emissions System Cleaner (part #4720) scrubs away contaminants, soot, carbon build-up and oily residue from the catalytic converter and the rest of the exhaust system, removes inorganic deposits, and restores functionality. It clears common OBD codes, turns off check engine lights, saves gas, and is guaranteed to help the vehicle pass emissions testing. It’s easy to use: Just pour it into the gas tank and drive.
   

“Paying attention to the signs of trouble your car gives you can make the difference between spending $30 to clean and restore the emissions system and spending $3,000 to replace a failed catalytic converter,” advises Clay Parks, vice president of development for Rislone.

About Rislone

Based in Holly, Michigan, Rislone has been America’s best-selling engine treatment brand for more than 100 years. All Rislone products are made in the USA and are available where auto parts are sold. Rislone is ISO 9001 certified. Learn more about Rislone Cat Complete Fuel, Exhaust and Emissions System Cleaner and the rest of Rislone’s full line of premium automotive chemicals at Rislone.com.

A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/ad5e9563-2084-4bce-8482-fcebf29f06e9

Media Contact:
Kristen Simpson
Simpson Communications, LLC
(216) 991-4297
kristen@simpsoncomm.com