The catalytic converter red flag
When it goes, it may point to other problems
Wi th l i ttle doubt, one of the most wallet- s hocking repair estimates a driver can get for their ride is the replacement of a catalytic converter. On some mainstream vehicles, these emission control devices can easily exceed $ 1,500 just for the part, not to mention the cost of installation. Fortunately, only a minority of car owners are faced with this situation, but when it happens, you need to ask some questions.
First, catalytic converters really are designed for the life of a vehicle and when they fail, it’s almost always caused by external factors. About the only exception to this is when corrosion takes its toll on the metal shell or the pipes that make up the exterior construction of these hardy exhaust components.
Converters usually fail from upstream issues; either an improper fuel mix or engine problem. When a converter replacement is required, if any existing fault that led to this isn’t detected and rectified, you can almost count on needing another converter during the life or the vehicle.
In many cases, these external faults can be traced to faulty sensors, or fuel/air delivery problems pumping too much unburned fuel into the exhaust. There, the 1,000- plus degree operating temperature of the converter will ignite it. This can overheat the filtration component inside the converter, to the point where it can plug the fine honeycomb- style air passages or make them extremely brittle, allowing them to crack when the car travels over a sharp bump.
Another common reason is an engine head or gasket failure, allowing coolant to enter the air/fuel intake system. Engine coolant is great stuff — until it drenches the inside of a converter.
So, if your tech tells you your ride needs a new catalytic converter and nothing else, you might need a second opinion.
When it comes to options for replacements, there are choices other than the original automaker’s new parts. Many aftermarket companies list converters for a wide range of popular vehicles, available from independent and chain auto- parts stores. But be warned: they’re not always cheaper than dealership prices, so some shopping around is a must.
Direct- fit units, complete with the correct pipes and flanges, are always your best bet, unless your tech is a skilled welder and can cut out the old one and refit a “one-size-fits-all” unit.
Finding converters in salvage yards or recycler facilities is becoming harder, as much of their stock is purchased for their precious metals by ‘ miners’ looking to extract platinum, palladium, and rhodium from the innards of the catalytic converter.