Audi Repair

Reasons for a Malfunctioning Catalytic Converter in an Audi

Audi Catalytic Converter

Audi continues to be a popular import. The streets of Orange County are full of these trendy little automobiles. One problem Audi owners seem to experience, though, is premature failure of their catalytic converters. Let’s see why that might be.

What is the catalytic converter?

The catalytic converter is an important part of your Audi exhaust system. It is shaped similar to a muffler and contains a ceramic honeycomb infused with elements that help clean the noxious exhaust gases that would otherwise be expelled from the exhaust system. It’s quite common for Audi vehicles to have either 2 or 4 catalytic converters.

Scrubbing the Exhaust in 3 Steps

Catalytic converters are designed to eliminate toxic gases from the vehicle’s exhaust. The catalytic converter is divided into sections referred to as beds. Each bed completes a step in the process of cleaning the exhaust expelled from your car.

1. The first bed is called the reduction bed. It’s coated with rhodium and serves to reduce harmful nitrous oxide gases back into their individual elements of nitrogen and oxygen.

2. The mid-section of the catalytic converter is known as the oxygen storage bed. It’s coated with cerium. The function of this section is to maintain the ideal level of oxygen for use by the final section of the converter. It stores and releases the oxygen that is freed from nitrogen in the first chamber.

3. The final chamber, the oxidizing bed, is coated with platinum and palladium. In this bed, combustion of any remaining carbon monoxide is completed. The oxygen is also used to burn off any raw hydrocarbons remaining in the exhaust gases.

What causes premature malfunction of the catalytic converter?

A catalytic converter generally does not malfunction in and of itself. Failure of the catalytic converter is almost always related to some malfunction in the engine. The primary cause of catalytic converter is overheating. This causes the internal components of the converter to melt and essentially “clog” or “plug” the passage through. Aside from an engine issue, the only other reason for a catalytic converter to fail is damage caused by impact (i.e. Remember that curb you went over?)

Check your engine

Catalytic converters overheat when there is an engine issue that results in too much raw fuel being dumped into the exhaust system. Common engine problems that can cause this to happen are:

  • Leaky fuel injectors
  • Incorrect or corroded spark plugs
  • An intake manifold air leak
  • Incorrect ignition timing or a bad ignition coil
  • Faulty oxygen sensor
  • Leaking oil or coolant
  • Leaking fuel pressure regulator

Symptoms of Catalytic Converter Failure

Probably the most frequent symptom of catalytic converter failure is an illuminated check engine light. Since other engine issues can trigger this alert, it’s important to have it checked by a professional Audi mechanic as soon as possible. Other symptoms include:

  • Failed emissions test-a trouble code should be stored in the testing computer indicating a problem with the catalytic converter
  • A sulfurous (rotten egg) smell to the exhaust from unburnt fuel in the exhaust exiting the tailpipe
  • Reduction in engine power from a blocked exhaust system
  • Rattling sound under the automobile from broken pieces of the honeycomb construction inside the converter

The Solution

A malfunctioning catalytic converter has to be completely replaced. It’s best to have this done by a professional auto repair shop, so the engine can be evaluated to determine the cause of the damage to the converter. Simply replacing the converter without correcting the underlying problem will just result in another damaged catalytic converter. Under these circumstances, the warranty on the second converter will likely not cover its replacement.

Broken Catalytic Converter

How We Can Help

Here at Mark Douglas Motorworks, our Audi technicians have the specialized knowledge and expertise you need to take proper care of your European import. Your Audi deserves to be handled by Audi specialists who can track down the source of your catalytic converter failure and repair the engine issue in addition to quickly and professionally replacing your converter itself. We pride ourselves on providing superb dealership alternative service to all our high-end automobile clients.

With locations convenient to Orange County, including Mission Viejo, Lake Forest, Costa Mesa, Irvine, Huntington Beach, Laguna Hills, and Laguna Niguel, CA we’re just around the corner, providing you with affordable, expert service.