Catalytic Converter Service Video

The catalytic converter sits in the exhaust system between the engine and the muffler. It converts harmful gases, such as carbon monoxide and unburned hydrocarbons, into less harmful compounds before they exit the tailpipe. This video shows where the catalytic converter mounts on a typical vehicle. It compares a healthy converter substrate with one that has melted or fractured. It also explains why a P0420 check engine code may indicate a catalytic converter problem rather than a faulty oxygen sensor.

Inside the catalytic converter, a ceramic honeycomb substrate is coated with platinum, palladium, and rhodium. As exhaust gases pass over this coating, chemical reactions convert harmful pollutants into less harmful compounds.

The catalytic converter can fail when its substrate cracks from thermal shock or becomes clogged with contaminants from an engine burning oil. Theft-related damage can also hollow out the converter, leaving it unable to function. The downstream oxygen sensor may detect reduced converter efficiency and signal the ECU.

Common signs of catalytic converter problems include a rotten-egg smell at idle, rattling underneath during acceleration, sluggish throttle response, and a check engine light. A cut exhaust pipe and loud roaring noise beneath the vehicle may indicate catalytic converter theft rather than normal wear.

Stop-and-go driving on Kingshighway and William Street exposes the catalytic converter to repeated heating and cooling cycles. Over time, these temperature changes can weaken the substrate and accelerate internal deterioration, especially in older vehicles. If diagnosis points to an upstream cause rather than the converter itself, check engine light diagnostics is the right next step before any exhaust work begins.

At Parks Automotive, we start by scanning for stored and pending trouble codes. We also inspect the catalytic converter for physical damage or missing hardware. Then, we measure exhaust backpressure or temperature differences across the converter to check for restrictions. We do not replace a converter without first ruling out a failing oxygen sensor, a misfire, or an oil-burning issue that could ruin a new one within weeks.

Catalytic converter work falls under our broader exhaust system repair services. We handle everything from flex-pipe leaks and manifold cracks to complete catalytic converter replacement. When replacement is necessary, we use direct-fit units that meet EPA requirements for your vehicle.

Call Parks Automotive at (573) 335-2599 to schedule a diagnosis, or find your trusted Cape Girardeau car care shop online. Drivers from Jackson and Scott City bring their vehicles to us for exhaust and emissions work as part of routine repairs