Car care · Elgin Auto Sales & Service Center · Elgin, IL
What Is a Catalytic Converter?
A catalytic converter is part of your vehicle's exhaust system and its emissions controls. You rarely think about it until something goes wrong. This guide explains what it is and how to protect it, using two 2026 owner's manuals, the 2026 Ram 1500 Owner's Manual and the 2026 Toyota Corolla Owner's Manual, as manufacturer examples.
Unleadedfuel only
No routinemaintenance under normal conditions
Flashing MILmeans service right away
Hotkeep it off dry grass and leaves
The short answer
A catalytic converter is an emissions control device in the exhaust system. The 2026 Ram 1500 Owner's Manual calls the catalyst an emissions control device, and the 2026 Toyota Corolla Owner's Manual refers to its three-way catalytic converters. Under normal operating conditions it needs no maintenance, but it depends on a properly running engine: misfires, a flashing check engine light and leaded fuel can damage it, and a malfunctioning converter can run hot enough to start a fire if you park over dry plants or leaves.
What a catalytic converter is
The catalytic converter sits in the exhaust system and is part of the vehicle's emissions control system. The 2026 Ram 1500 Owner's Manual describes the catalyst as an emissions control device, and the 2026 Toyota Corolla Owner's Manual calls the converters on the Corolla three-way catalytic converters that are part of its emission control system.
Modern vehicles also watch over it. The Ram manual explains that the onboard diagnostic system (OBD II) monitors the emissions, engine and transmission control systems and turns on the Malfunction Indicator Light (MIL), the check engine light, when one of those systems needs service.
From the 2026 Ram 1500 Owner's Manual (publication 104308_26_DT, edition E2; Exhaust System, page 322; Onboard Diagnostic System, page 149) and the 2026 Toyota Corolla Owner's Manual (publication OM12W27U; Fuel information, page 392), read November 4, 2026.
It needs unleaded fuel
The 2026 Ram 1500 Owner's Manual says the catalytic converter requires the use of unleaded fuel only, and that leaded gasoline will destroy the effectiveness of the catalyst as an emissions control device and may seriously reduce engine performance and cause serious damage to the engine. It also notes that the use of leaded gasoline is prohibited by federal law.
The 2026 Toyota Corolla Owner's Manual gives the same warning: do not use leaded gasoline, because it can damage the vehicle's three-way catalytic converters and cause the emission control system to malfunction.
From the 2026 Ram 1500 Owner's Manual (pages 322 and 368) and the 2026 Toyota Corolla Owner's Manual (page 392), read November 4, 2026.
What can damage a catalytic converter
The 2026 Ram 1500 Owner's Manual lists these causes and precautions:
Engine misfire
Damage can result if the vehicle is not kept in proper operating condition. If the engine misfires or loses performance, have it serviced promptly, because continued operation with a severe malfunction could overheat the converter.
A flashing check engine light
If the MIL is flashing while the engine is running, the manual says severe catalytic converter damage and power loss will soon occur and immediate service is required.
Push or tow starting
Do not try to start the vehicle by pushing or towing it. Unburned fuel could enter the converter and, once the engine starts, ignite and damage the converter and vehicle.
Shutting off the ignition while moving
Do not interrupt the ignition when the transmission is in gear and the vehicle is in motion.
Idling with ignition parts disconnected
Do not idle the engine with ignition components disconnected or removed, or for prolonged periods during very rough idle or malfunctioning operating conditions.
An out-of-tune engine
An out-of-tune engine or certain fuel or ignition malfunctions can cause the converter to overheat.
From the 2026 Ram 1500 Owner's Manual (Exhaust System and catalytic converter cautions, pages 322 to 323; Engine Check/Malfunction Indicator Warning Light, page 144; starting cautions, page 187; Fuel System Cautions, page 368), read November 4, 2026.
Warning signs to take seriously
A flashing check engine light is the most urgent one. The 2026 Ram 1500 Owner's Manual says the MIL may flash to alert serious conditions that could lead to immediate loss of power or severe catalytic converter damage, and that the vehicle should be serviced as soon as possible. For a steady light, see our guide on what to do when the check engine light comes on.
Smell and smoke are the other clue. The Ram manual says a pungent burning odor or some light smoke may mean the engine is out of tune or malfunctioning and may need immediate service. It adds that in unusual situations involving grossly malfunctioning engine operation, a scorching odor may suggest severe and abnormal catalyst overheating; if that happens, stop the vehicle, turn off the engine and let it cool, then get service right away.
From the 2026 Ram 1500 Owner's Manual (pages 144, 322 and 368), read November 4, 2026.
Heat and fire risk
A catalytic converter and the exhaust around it get hot. The 2026 Ram 1500 Owner's Manual warns that a malfunctioning catalytic converter can reach higher temperatures than in normal operating conditions, which can cause a fire if you drive slowly or park over flammable substances such as dry plants, wood or cardboard. It also says a hot exhaust system can start a fire if you park over materials that can burn, such as grass or leaves.
In an Illinois fall, that means avoiding parking on tall dry grass or a pile of leaves.
From the 2026 Ram 1500 Owner's Manual (pages 144 and 322), read November 4, 2026.
Does a catalytic converter need maintenance?
Not on its own. The 2026 Ram 1500 Owner's Manual says that under normal operating conditions the catalytic converter will not require maintenance, but that it is important to keep the engine properly tuned to assure proper catalyst operation and prevent possible catalyst damage. In practice, that means following your vehicle's maintenance schedule and fixing misfires and check engine lights promptly. See our car maintenance schedule basics.
The manual also notes that intentional tampering with emissions control systems can result in civil penalties.
From the 2026 Ram 1500 Owner's Manual (page 322), read November 4, 2026.
Exhaust and check engine service at Elgin Auto Sales & Service Center
Our service department works on all makes and models. If your check engine light is on or flashing, you smell something burning from the exhaust, or the engine is running rough, tell us what you noticed and our technicians will take a look.
Our service department at 1200 E. Chicago St. in Elgin is open Monday to Friday 8 a.m. to 5 p.m. and Saturday 8 a.m. to 4 p.m., and is closed Sunday. Schedule service, see our service specials or get directions.
Catalytic converter FAQ
What does a catalytic converter do?
It is an emissions control device in the exhaust system. The 2026 Ram 1500 manual calls the catalyst an emissions control device, and the 2026 Toyota Corolla manual refers to its three-way catalytic converters as part of the emission control system.
Does a catalytic converter need regular maintenance?
Not under normal operating conditions, according to the 2026 Ram 1500 manual. Keeping the engine properly tuned is what protects it.
Can a misfire damage the catalytic converter?
Yes. The 2026 Ram 1500 manual says engine misfire or other loss of performance should be serviced promptly, because continued operation with a severe malfunction could overheat and damage the converter.
What does a flashing check engine light mean for the converter?
The 2026 Ram 1500 manual says a flashing MIL means severe catalytic converter damage and power loss will soon occur and immediate service is required.
Why should I not park on dry grass?
A hot exhaust system, or a malfunctioning catalytic converter, can start a fire if it contacts dry grass, leaves or other materials that can burn, according to the 2026 Ram 1500 manual.
Can I push start a car with a catalytic converter?
No. The 2026 Ram 1500 manual says not to push or tow start the vehicle, because unburned fuel could enter the converter and ignite once the engine starts.
What are your service hours?
Monday to Friday 8 a.m. to 5 p.m. and Saturday 8 a.m. to 4 p.m. We are closed Sunday.
Check engine light or burning smell?
Schedule service at 1200 E. Chicago St. in Elgin and tell us what you noticed.
Sources
Descriptions, cautions and maintenance guidance are from the 2026 Ram 1500 Owner's Manual (publication 104308_26_DT, edition E2) and the 2026 Toyota Corolla Owner's Manual (publication OM12W27U), used as manufacturer examples and read November 4, 2026. Check your own owner's manual for your vehicle. Service hours are from our service page, checked the same day.
- 2026 Ram 1500 Owner's Manual (Exhaust System; Engine Check/Malfunction Indicator Warning Light; Onboard Diagnostic System; Fuel System Cautions), Ram / Mopar, read November 4, 2026
- 2026 Toyota Corolla Owner's Manual (Fuel information), Toyota, read November 4, 2026
- Service department and service hours, Elgin Auto Sales & Service Center
- Home page: address and all makes and models, Elgin Auto Sales & Service Center