Does You Subaru Need a Catalytic Converter?

The catalytic converter in your Subaru is located between the engine and the muffler. Its job is to convert dangerous engine chemicals into harmless ones and reduce airborne pollution. In time your converter can become worn, blocked, or damaged, and you’ll need a repair or replacement at your Subaru dealer. These are some signs that your converter is in trouble.

Black Exhaust Smoke

Exhaust smoke is usually thin and wispy and is almost invisible. If your exhaust smoke suddenly changes to thick, black smoke your converter has failed. The change in color and consistency of the smoke is due to the presence of carbon monoxide, hydrogen sulfide, and other gases produced by combustion.

Your converter uses a combination of great heat, chemical reactions, and high pressure to convert combustion chemicals into less harmful ones. If your converter has failed due to age or damage, this conversion won’t take place. We’ll need to examine your converter to find the cause of the problem, and then we’ll repair or replace it, and your exhaust smoke will return to normal.

Failed Oxygen Sensor

Air is a vital component of combustion, and efficient combustion requires a precise mixture of air to fuel. Oxygen is so important to your engine that there are two sensors dedicated to monitoring it. The information provided by these sensors is used by your car’s computer to adjust the level of air. These sensors can fail over time, and this can result in converter damage.

If a failed sensor leads to a reduced level of air in your engine, the engine becomes fuel-rich. A fuel-rich engine prevents most of the fuel used for combustion from burning. The unburnt fuel is dumped into the converter, which raises the converter’s internal temperature and burns it out. We’ll examine your converter and replace it if necessary.

Blocked Converter

The chemical reactions in the converter produce carbon. This carbon can build up and block the exit into the exhaust. A blocked converter prevents the converted gases from escaping your car, and they’re forced back into the engine. The exhaust gases increase engine pressure, and they also raise the fuel-to-air ratio.

The increased pressure and high fuel concentration can lead to misfiring or stalling. You may even experience your engine shutting down within seconds of starting. This will happen when the pressure in the engine is too high, and combustion can’t be satisfactorily completed. We can solve a blocked converter problem by removing the converter and cleaning it. Once the blockage is removed, your converter and engine will work normally gain.

If you experience any problems with your converter, call our service department at Puente Hills Subaru.

Posted in Subaru Service | No Comments »