The catalytic converter is an essential element of any modern exhaust system. These components often make the news since thieves are typically fond of them, but they're more than just tempting theft targets. Every car has one or more catalytic converters (sometimes known simply as "cats") that chemically convert harmful exhaust gases into safer emissions.
Although the catalytic converter's purpose is environmental, a failed cat can directly impact your vehicle's performance. You may also be unable to pass state emissions with a faulty converter. These components often wear out due to other underlying issues, but it's still critical to recognize the signs of failure. These three indications will tell you if it's time to replace this crucial exhaust component.
1. Noticeable Loss of Power
Your vehicle's manufacturer designed its exhaust system to provide maximum performance and fuel efficiency with minimal environmental impact. Your catalytic converter helps to achieve this goal, but it's also a component that's in line with the rest of your exhaust. When the converter begins to fail, it can create an obstruction that restricts exhaust flow.
Although modern exhaust systems are too sophisticated to assume that more flow always means more power, any change in the designed characteristics of the system can cause problems. A plugged catalytic converter alters the expected rate that your vehicle can remove exhaust gases, resulting in reduced overall performance and making your car feel sluggish.
2. Loss of Fuel Efficiency
Restricted flow through your exhaust system impacts the careful balance of fuel to air in your combustion chamber. Although a loss of power might be the most immediately apparent symptom, this situation can also impact fuel efficiency. Drivers with failing catalytic converters often notice a marked reduction in their vehicle's miles per gallon.
If your car allows you to track your current and average fuel efficiency, it's always a good idea to monitor these values weekly. Changes in your expected fuel consumption are a great way to spot trouble with your vehicle, even when looking beyond your exhaust system.
3. Check Engine Codes
Your car's onboard diagnostic system has a specific code to indicate a fault with the catalytic converter. This code triggers when the downstream oxygen sensor detects an issue relative to the values in the upstream oxygen sensor. Believe it or not, this is not necessarily a slam dunk diagnosis. Since your vehicle relies on oxygen sensors to trigger this code, bad O2 sensors can also be at fault.
If you receive a P0420 code for insufficient catalyst system efficiency, always check for other symptoms before replacing the catalytic converter. Since these parts are expensive, it's often best to rule out other possibilities before proceeding with a repair.
For more information about exhaust system repair, contact a mechanic near you.