Acura Legend Catalytic Converters: Everything You Need To Know

Acura Legend Catalytic Converters: The Acura Legend was a luxury sedan from 1986 to 1995. All Legends came with V6 engines and used two catalytic converters – one on each exhaust manifold bank. OEM Legend converters contained a ceramic honeycomb substrate coated with platinum, palladium, and rhodium catalysts.

Direct-fit replacement Acura Legend Catalytic Converters are available from aftermarket brands like Bosal, Eastern Catalytic, and Walker. Proper inlet/outlet dimensions and flange style must match the original converters. CARB-compliant converters are required for Legends sold in California.

Read More: Acura Integra Catalytic Converters

Specific Details on the Acura Legend Catalytic Converters

Recommended Replacement Converters:

  • Bosal Direct Fit Converter – Part #44350
  • Eastern Catalytic EPA Converter – Part #31515
  • Walker Ultra EPA Catalytic Converter – Part #54019

Troubleshooting Tips for Acura Legend Catalytic Converters:

  • Check for P0420/P0430 codes pointing to converter failure using an OBD2 scanner.
  • Listen for rattling noises from the exhaust, indicating internal damage.
  • Inspect oxygen sensor performance upstream and downstream of converters.
  • Look for reduced performance, increased fuel usage, and rotten egg smells.
  • Use Catalytic Cleaner for catalytic converting cleaning

Installation Tips:

  • Always replace the exhaust inlet/outlet gaskets when installing the new Acura Legend converters. High-temperature silicone sealant can also be used to seal connections.
  • The inlet/outlet pipe diameter is 2.5″. Ensure the replacement converters have the proper 2.5″ inlet and outlet ports.
  • When secured to the manifolds, use a torque wrench to tighten the converter mounting nuts/bolts to the proper spec of 22-27 ft-lbs.
  • Carefully detach and reattach the oxygen sensors from the original converters to the new ones in their same locations.
  • Clear any check engine codes with a scan tool after installing the new Legend converters. This will reset fuel trim parameters and monitor operation.

Read More: Acura ILX Catalytic Converters

How To Replace Catalytic Converters on an Acura Legend


The Legend uses two catalytic converters, one on each exhaust manifold bank. The new converters must be bolted into the original mounting positions for proper exhaust flow.

Exhaust Seals:

When installing the Acura Legend catalytic converters, use new gaskets to seal the inlet and outlet flanges. Apply high-temperature silicone sealant as well to prevent leaks.

Oxygen Sensors:

Carefully detach and reattach the oxygen sensors from the old converters to the new ones. Position the upstream and downstream sensors properly.

Inspect Other Components:

When replacing the Legend converters, inspect the exhaust manifolds, mounts, and pipes. Look for any leaks or damage that needs addressing.

Post-Installation Check:

After installing the new Legend converters, clear any codes and road test the vehicle. Verify the catalyst efficiency monitors are set to ready and that no check engine lights return.

Let me know if you need any other details on properly replacing the two catalytic converters on Acura Legend models! Proper procedures are crucial for emissions compliance.

FAQs About Acura Legend Catalytic Converters

What is the purpose of a catalytic converter in my Acura Legend?

A catalytic converter in your Acura Legend reduces harmful emissions by converting pollutants like carbon monoxide into less harmful substances.

How long does a catalytic converter typically last in an Acura Legend?

The lifespan of a catalytic converter in an Acura Legend can vary, but on average, it may last anywhere from 70,000 to 100,000 miles, depending on driving conditions and maintenance.

What are the signs of a clogged catalytic converter in my Acura Legend?

Signs of a clogged catalytic converter may include reduced engine performance, decreased fuel efficiency, and illuminated dashboard warning lights such as the Check Engine Light.

Can I clean a clogged catalytic converter, or must I replace it?

Cleaning a clogged catalytic converter is not typically recommended. It’s often more practical to replace it, as cleaning may only partially restore its function.

How much does replacing a catalytic converter in an Acura Legend cost?

The cost of replacing a catalytic converter can vary depending on the model year and location, but it generally ranges from $200 to $1,500 or more.

What factors affect the price of a new catalytic converter for my Acura Legend?

The price of a new catalytic converter can be influenced by factors such as the brand, materials used, and whether it’s an original equipment manufacturer (OEM) or aftermarket part.

Can I sell my old Acura Legend catalytic converter as scrap?

Yes, you can often sell your old catalytic converter as scrap. It contains valuable metals like platinum, palladium, and rhodium, which can fetch a decent scrap price.

What is the best cleaner for maintaining a catalytic converter in my Acura Legend?

Using a fuel system cleaner that is designed explicitly for catalytic converters is a good option. Be sure to choose a product that is compatible with your vehicle.

Are there any legal regulations regarding catalytic converters in Acura Legends?

Yes, there are regulations governing catalytic converters to control emissions. Ensuring replacement converters comply with local and federal emission standards is essential.

Can I extend the life of my Acura Legend’s catalytic converter through regular maintenance?

Yes, regular maintenance, such as timely engine tune-ups and addressing issues that can lead to excess emissions, can help extend the life of your catalytic converter.

I am Nicolas, an automobile engineer with over 5 years of experience in exhaust systems and catalytic converters. I am passionate about learning and understanding how things work, and I am always looking for new ways to improve the performance and efficiency of automotive exhaust systems.

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