AutoShack Exhaust Manifold Catalytic Converter Passenger Side Review: Supports 5.6L V8 Engines for Multiple Models

Where the Exhaust Manifold Converter Fits

The AutoShack Exhaust Manifold Converter is for owners of 5.6L V8 trucks and SUVs who need an EPA-compliant replacement that matches OE part number 674-843, providing a complete Exhaust Manifold with Converter for vehicles like the Nissan Armada and Titan.

Restoring your vehicle’s exhaust system to factory standards ensures that your 5.6L V8 engine runs with the correct backpressure and emission profile. A correctly fitted manifold allows for a seamless transition from the cylinder head to the exhaust system.

The AutoShack Exhaust Manifold Converter achieves this by offering an EPA-compliant design specifically for the 2004-2015 Nissan and Infiniti lineup. It is priced at approximately $238.99 and holds a 4.2 rating from 38 buyers who value its specific application fit.

Our comparison involved a systematic research analysis of the exhaust manifold converter options we evaluated. This review is intended for truck owners who require a professional-grade replacement that meets specific vehicle requirements without the need for welding.

For a detailed performance breakdown, see our full review of the Nissan Altima Converter.

The Short Answer on the Exhaust Manifold Converter

Comparing weight is crucial, so learn how to choose the correct weight for your manifold.

The Specifications That Matter

The inclusion of the specific OEM Part Number 16479 674-843 674-843 ensures the manifold geometry aligns with your specific engine block casting.

Before You Buy: Exhaust Manifold Converter Checklist

The first thing to check is your specific vehicle’s OE part number to ensure the manifold geometry aligns with your engine block casting.

• ☐ Confirm your vehicle matches the 16479 674-843 interchange number
• ☐ Verify your engine is a 5.6L V8 drivetrain
• ☐ Check that your vehicle is not registered in California, Colorado, New York, or Maine
• ☐ Confirm your vehicle is a 2004 Nissan Pathfinder, 2004-2015 Armada, 2004-2015 TITAN, 2008-2012 Pathfinder, 2012-2016 NV3500, 2012-2016 NV2500, or 2004-2010 INFINITI QX56
• ☐ Budget for professional installation as the manufacturer recommends a qualified installer

You should not buy this exhaust manifold converter if your vehicle is located in a state with specific emissions laws that prohibit this product’s use.

Performance: What the Specs Deliver

5.6L V8 Engine Compatibility

The AutoShack Exhaust Manifold Catalytic Converter Passenger Side supports the 5.6L V8 engine found in several heavy-duty and SUV platforms. This specific fitment covers the 2004-2015 Armada, the 2004-2015 TITAN, and the 2012-2016 NV2500 and NV3500 models. Because it matches the 5.6L V8 geometry, you can expect the Exhaust Manifold Converter to align with the specific cylinder port layout of these high-torque engines.

Regarding exhaust flow compared to the original factory part, the data indicates this unit is designed to maintain stock flow levels. Since the Exhaust Manifold Converter uses a standard configuration for these specific vehicle models, it is intended to restore original performance rather than provide a high-flow modification. You should verify your specific vehicle’s VIN using a fitment tool to ensure the 674-843 interchange matches your engine casting.

Hardware Included for Assembly

The Exhaust Manifold Converter includes the hardware required for assembly, which simplifies the installation process. Having the necessary bolts and fasteners included means you do not need to source additional mounting hardware to secure the unit to the engine head. This ensures that the 15.4-pound component remains stable under the high thermal stress of the V8 engine.

EPA Compliant Design

The Exhaust Manifold Converter features an EPA Compliant design to meet federal emissions standards. This compliance ensures that the catalytic substrate meets the necessary chemical requirements for street legality in most states. However, this specific unit is not legal for sale or use in California, Colorado, New York, or Maine, so you must confirm your local state regulations before purchasing.

Owners of a Honda vehicle can find our spec breakdown of the Civic Exhaust Manifold.

How the Exhaust Manifold Converter Compares to Alternatives

The Exhaust Manifold Converter provides a significant cost advantage over several alternatives, priced at $238.99. It ranks as the 2nd cheapest option among the six exhaust manifold converters we evaluated.

• The Exhaust Manifold Converter costs $10.89 less than the M-AUTO Exhaust Manifold Catalytic Converter Jeep Wrangler.
• The Exhaust Manifold Converter costs $16.01 less than the 674-318 674-319 Front and Rear Manifold Catalytic Converters.
• The Exhaust Manifold Converter costs $18.62 less than the APDTY 112869 Exhaust Manifold Catalytic Converter Assembly.
• The Exhaust Manifold Converter costs $35.97 less than the Pacesetter 750032 Manifold Catalytic Converter.
• The 674-292 52022459AA Manifold Catalytic Converter is $33.99 cheaper than the Exhaust Manifold Converter.

If you require a lower entry price point for a Ram ProMaster, the 674-292 52022459AA Manifold Catalytic Converter is the better choice for that specific application.

Regarding durability and substrate quality, the data confirms the Exhaust Manifold Converter is EPA Compliant, which indicates the substrate meets federal emissions standards for chemical composition. Because the provided data does not specify the substrate material or thermal treatment, you should verify the substrate type and heat-treatment specifications with the manufacturer to ensure it will not fail prematurely under high-heat conditions.

The Exhaust Manifold Converter: Remaining Questions

Is the AutoShack Exhaust Manifold Catalytic Converter Passenger Side worth the $238.99 price point?

The price for this Exhaust Manifold Converter is a mid-range investment compared to generic alternatives. You should weigh the cost against the fact that this unit includes hardware for assembly and is designed for specific 5.6L V8 applications like the Nissan Titan and Armada.

Is this converter legal to use in California, New York, or other states?

No, this Exhaust Manifold Converter is not legal for sale or use in California, Colorado, New York, or Maine. You must verify your local emissions regulations before ordering, as these specific states have stricter requirements than the standard EPA Tier 3 / Euro 6 standards.

Will this fit my 2004 Nissan Pathfinder?

Yes, the Exhaust Manifold Converter is a direct replacement for the 2004 Nissan Pathfinder. It is designed to match the 5.6L V8 engine geometry and the 674-843 interchange number.

Does this unit require welding during installation?

No welding is required for this Exhaust Manifold Converter as it comes as a complete assembly. However, because of the complexity of manifold geometry, professional installation is recommended to ensure the unit aligns correctly with the cylinder ports.

Is the Exhaust Manifold Converter Right for You?

The Exhaust Manifold Converter suits 5 kinds of buyer and is the wrong choice for 4 jobs, listed below with the reason for each.

Where to Buy the Exhaust Manifold Converter

These retailers sell Exhaust Manifold Converter generally – we do not track which of them has this particular model in stock, so check availability and the current price with the retailer before making a trip.

• Advance Auto Parts (online and physical stores) — local availability and in-store returns
• RockAuto (online only) — extensive catalog breadth and competitive pricing
• Summit Racing Equipment (online only) — specialist performance and aftermarket options
• Amazon (online only) — wide variety of third-party brands
• eBay (online only) — finding specific OE replacements and used parts
• AutoZone (online and physical stores) — local availability and in-store returns
• O’Reilly Auto Parts (online and physical stores) — local availability and in-store returns

Final Verdict on the Exhaust Manifold Converter

You need a replacement for a 5.6L V8 engine in a 2004 Nissan Pathfinder or a 2004-2015 Armada, and the AutoShack Exhaust Manifold Converter is the correct choice at around $238.99.

This exhaust manifold converter ranks well for its application, backed by a 4.2 rating from 38 buyers who confirmed its fitment for these specific truck and SUV models.

Skip it if: you are located in California, Colorado, New York, or Maine, as this unit is not legal for sale or use in those states.

Check the current price on Amazon