Aftermarket Catalytic Converters: Alternatives to OEM, But Choose Wisely

When it comes to automotive components, the term “aftermarket” refers to parts not made by the original equipment manufacturer (OEM) for a particular vehicle. Aftermarket catalytic converters have become increasingly popular as a cost-saving alternative to their more expensive OEM counterparts. However, making the right decision is important to avoid compromising emissions compliance or facing unforeseen issues.

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The temptation of aftermarket catalytic converters lies in their potential for significant cost savings, especially for older vehicles where OEM parts have been discontinued. Yet, this market is rife with quality disparities, making due diligence essential. In this comprehensive guide, we’ll explore the pros and cons of going the aftermarket route and performance considerations and provide insights to help you make the right choice for your vehicle catalytic converter and budget.

Key Takeaways Non-OEM Catalytic Converter

Research is paramount when considering aftermarket catalytic converters to ensure quality, compliance, and proper fitment.
While cost savings are appealing, prioritize emissions compliance and overall reliability to avoid potential legal issues or premature failure.
Consult experienced professionals for installation and troubleshooting to maximize the lifespan of your aftermarket converter.
For performance enthusiasts, high-flow aftermarket converters can provide modest power gains while remaining street-legal but managing expectations.
When deciding between aftermarket and OEM options, weigh your vehicle’s needs, budget, and commitment to emissions regulations.

What Are The Some Pros And Cons Of An Aftermarket Catalytic Converter?

Aftermarket catalytic converters offer several benefits and drawbacks compared to OEM (Original Equipment Manufacturer) converters. Here are some key points to consider:

What Are the Advantages of Aftermarket Catalytic Converters?

Lower Cost: One of the primary draws of aftermarket catalytic converters is their lower price tag than their OEM equivalents. This cost advantage can be substantial, often making aftermarket units appealing when working with a tight budget.

Availability: As vehicles age, finding OEM replacement parts can become increasingly challenging, especially for discontinued models. Aftermarket catalytic converters offer a more readily available solution, ensuring you can keep your beloved ride on the road.

Faster Installation: Non-OEM catalytic converters are designed to be installed quickly, which can save time and money compared to OEM converters.

Increased Accessibility: Third-party cat converters are often designed to be more accessible, making it easier to install and maintain.

What Are the Disadvantages of Aftermarket Catalytic Converters?

Variable Quality: The aftermarket catalytic converter landscape is mixed regarding quality. While some manufacturers prioritize robust construction and adherence to emissions standards, others may cut corners, resulting in subpar performance and potential legal issues.

Fitment Issues: Many aftermarket catalytic converters are marketed as “universal,” but this one-size-fits-all approach can lead to compatibility problems. Improper fitment may necessitate cutting, welding, and other modifications, increasing installation costs and complexity.

Shorter Lifespan: Some aftermarket catalytic converters may not last as long as their OEM counterparts due to lower-grade materials and construction methods. This can lead to more frequent replacements and increased long-term costs.

Potential Warranty Issues: Installing an aftermarket catalytic converter could void your vehicle’s manufacturer warranty, especially if it contributes to the failure of other emissions components or is improperly installed.

What Should I Research Before Buying an Aftermarket Catalytic Converter?

Aftermarket catalytic converters can be a minefield of varying quality and hidden traps. To make sure you get the right one for your car, it’s essential to do your homework. Here are some key considerations:

Research is Key

Extensive research is essential before committing to a particular brand or model. Look for manufacturers with a solid reputation for producing high-quality exhaust components, and verify that the converter you’re considering is certified as emissions-compliant for your specific vehicle (EPA or CARB certification).

“Direct Fit” vs. “Universal”: Which Is Better?

While “universal” catalytic converters may seem appealing from a cost perspective, they often require significant modifications for proper installation, potentially negating any initial savings. “Direct-fit” options, designed specifically for your vehicle, can simplify installation and reduce labor costs.

How Do Material Choices Affect My Catalytic Converter?

The materials used in an aftermarket catalytic converter can greatly impact its durability and performance. Stainless steel construction is generally preferable over plain steel, as it offers better resistance to corrosion and wear. Additionally, ensure that the precious metal loading (platinum, rhodium, palladium) is sufficient for your engine’s displacement and emissions requirements.

Does Proper Installation Matter?

Proper installation is critical, even with a high-quality aftermarket catalytic converter. Choose a mechanic with experience working with aftermarket components to ensure correct fitment, potential adjustments to oxygen sensor locations, and adherence to all applicable regulations.

Common Myths and Facts On Aftermarket Catalytic Converter

We try to dispel some common misconceptions surrounding aftermarket catalytic converters, providing accurate information to help readers make informed decisions.

Myth	Fact
Aftermarket catalytic converters are always low-quality and illegal.	While some low-quality options exist, many reputable manufacturers produce aftermarket converters that meet emissions standards and are legal for use. Look for EPA/CARB-certified units.
Installing an aftermarket converter will automatically void my warranty.	This depends on the specific warranty terms and conditions. Many allow aftermarket parts as long as they are properly installed and do not directly cause other component failures. Check with your warranty provider.
Any aftermarket converter will give me big power gains.	Most standard aftermarket converters are designed for emissions compliance, not performance gains. Only high-flow “performance” models may provide modest power increases by reducing exhaust restrictions.
Aftermarket converters never last as long as OEM units.	Lifespan varies based on the quality of materials and construction. Some well-made aftermarket converters can match or exceed the longevity of OEM units, while lower-grade ones may fail prematurely.
I can install a “universal” converter on any vehicle.	Universal converters often require significant modifications for proper fitment. Direct-fit options designed for your specific vehicle are generally preferable to ensure correct installation and operation.
Aftermarket converters are always cheaper than OEM replacements.	While aftermarket converters are typically less expensive upfront, lower-quality units may need more frequent replacement, potentially increasing long-term costs compared to a durable OEM converter.
Fuel additives and cleaners are safe to use with aftermarket converters.	Many manufacturers recommend avoiding fuel additives or cleaners, as they could potentially contaminate or damage the internal components of aftermarket converters.
I don’t need to adjust anything after installing an aftermarket converter.	Sometimes, you may need to reposition downstream oxygen sensors or reprogram the vehicle’s computer to accommodate the new converter for accurate readings and operation.

How To Install An Aftermarket Catalytic Converter?

Installing an aftermarket catalytic converter can be complex, so having the right tools and materials is essential. Here’s a step-by-step guide to help you through the process:

What Tools and Materials Do You Need?

Socket set and wrenches.
Penetrating oil or lubricant
Exhaust gasket or sealant
Welding equipment (if modifications are required)
Safety gear (gloves, goggles, etc.)
Jack stands and wheel chocks (for safe vehicle lifting)

Step-by-Step Guide For Installing A Third-Party Cat

Prepare the Vehicle: Ensure the vehicle is parked on a level surface and engage the parking brake. Raise the vehicle using jack stands or a lift, ensuring it’s securely supported.
Remove the Old Catalytic Converter: Locate the catalytic converter in your vehicle’s exhaust system. Use penetrating oil to loosen any stubborn bolts or connections. Carefully remove the converter, being mindful of any gaskets or seals needing replacing.
Prepare the New Converter: Inspect the new aftermarket catalytic converter for damage or defects. Ensure that all necessary gaskets or sealants are included or purchased separately.
Install the New Converter: Carefully position the new converter, ensuring proper alignment with the exhaust system. Secure it using the provided hardware or gaskets, following the manufacturer’s instructions.
Reattach the Exhaust System: Reconnect the remaining exhaust components, such as the muffler or resonator, ensuring proper alignment and a secure fit.
Check Clearances: Verify that the new catalytic converter has adequate clearance from other components, such as the suspension or body panels.
Lower the Vehicle: Carefully lower the vehicle back to the ground once everything is securely in place.
Start and Monitor: Check the engine for leaks or abnormal noises. Monitor the exhaust system during the initial driving period to ensure proper function.

Tips for Troubleshooting Your Non-OEM Cat

If you encounter any issues during installation, consult the manufacturer’s instructions or seek assistance from a professional mechanic.
Ensure all connections are tight and secure to prevent leaks or exhaust system damage.
If your vehicle has an oxygen sensor downstream of the catalytic converter, you may need to adjust its position or replace it to ensure accurate readings.

How to Diagnose and Fix Common Issues with An Aftermarket Catalytic Converter

Even with proper installation, aftermarket catalytic converters can sometimes experience issues or fail prematurely. Here’s how to identify and address common problems:

Identifying Symptoms of a Failing Aftermarket Catalytic Converter

Check engine light (or other emissions-related warning lights)
Decreased fuel efficiency
Reduced engine performance or power
Excessive exhaust smoke or odor
Rattling or other unusual noises from the exhaust system

What Causes an Aftermarket Converter to Malfunction?

Improper installation or fitment
Damage from road debris or impact
Excessive heat exposure (such as from engine misfire or overheating)
Clogging or contamination from external sources
Inherent quality issues or defects in the converter itself

Steps for Troubleshooting a Faulty Aftermarket Catalytic Converter

Check for Diagnostic Trouble Codes: Use an OBD-II scanner to read any stored codes related to the catalytic converter or exhaust system.
Visually Inspect the Converter: Look for signs of physical damage, such as dents, cracks, or excessive corrosion.
Check for Blockages: Use a mechanic’s mirror or borescope to inspect the interior of the converter for clogs or obstructions.
Verify Proper Installation: Ensure the converter is securely mounted and aligned within the exhaust system.
Replace Oxygen Sensors: If applicable, replace any faulty oxygen sensors that could be causing issues or providing inaccurate readings related to the catalytic converter.

Options for Repairing or Replacing a Damaged Aftermarket Catalytic Converter

Depending on the extent of the damage or malfunction, you may have a few options:

Repair: A skilled exhaust technician can sometimes repair minor issues like leaks or loose connections.
Replace with a New Aftermarket Unit: If the existing converter is severely damaged or clogged beyond repair, replacing it with a new one may be the most cost-effective solution.
Upgrade to an OEM Converter: While more expensive, replacing the aftermarket unit with a new OEM catalytic converter from your vehicle’s manufacturer can improve longevity and compatibility.

Preventative Measures for Extending the Lifespan of an Aftermarket Catalytic Converter

To maximize the service life of your aftermarket catalytic converter, consider the following preventative measures:

Proper Maintenance: Follow your vehicle’s recommended maintenance schedule, including regular oil changes and tune-ups, to minimize the risk of engine misfires or excessive exhaust temperatures.
Avoid Contamination: Use high-quality fuel and avoid any additives or substances that could potentially contaminate the catalytic converter.
Careful Driving: Minimize aggressive driving habits, such as excessive idling or rapid acceleration, which can strain the exhaust system.
Regular Inspections: Periodically inspect the catalytic converter and surrounding exhaust components for any signs of damage or potential issues.

What Is a High-Performance Catalytic Converter?

While most aftermarket catalytic converters aim to balance emissions compliance and cost savings, a subset of these products caters specifically to the performance enthusiast crowd. These high-flow or “performance” catalytic converters are designed to reduce exhaust flow restrictions while meeting legal requirements.

The Performance Angle

OEM catalytic converters are optimized for emissions control, but their internal structure can restrict exhaust flow. Performance aftermarket converters aim to minimize this restriction, potentially unleashing modest power gains while remaining street-legal.

How Do Performance Converters Differ From Standard Ones?

Larger Internal Honeycomb Structure: Performance converters often feature a larger honeycomb substrate with higher-flowing cells to reduce backpressure.
Thinner-Walled Substrates: Some units use thinner-walled ceramic or metallic substrates for improved exhaust flow compared to traditional thick-walled ceramic cores.
Optimized Pipe Diameters and Transitions: Careful attention is paid to maintaining smooth transitions and optimal pipe diameters throughout the converter to maximize exhaust gas velocity.

What Are the Potential Benefits?

Horsepower and Torque Gains: By reducing backpressure, performance catalytic converters can unlock slight to moderate horsepower and torque output increases, especially in modified or high-performance engines.
Improved Throttle Response: The freer-flowing exhaust can result in crisper throttle response and improved overall drivability.
Exhaust Note Changes: Some enthusiasts report a more aggressive or throaty exhaust note after installing a performance catalytic converter, though this can vary based on the specific application.

Who Should Consider a High-Performance Converter?

While the power gains from a performance aftermarket catalytic converter alone are often modest, certain groups may find them particularly appealing:

Enthusiasts with Modified Engines: Those who have already invested in other performance modifications, such as intake or exhaust upgrades, may see more tangible benefits from reducing exhaust restrictions.
Track/Race Cars: In environments where emissions regulations are less stringent or non-existent, maximizing exhaust flow can be a priority over strict emissions control.
Owners Prioritizing Performance: Some drivers may accept slight compromises in emissions output in exchange for extracting every last bit of power from their vehicle.

Reputable Brands for Performance Aftermarket Catalytic Converters

Choosing a reputable brand for producing high-quality, emissions-compliant products is crucial when considering a performance aftermarket catalytic converter. Some manufacturers that specialize in this segment include:

Magnaflow
Flowmaster
Borla
Eastern Catalytic
Walker

However, it’s essential to research thoroughly and look for independent reviews, dyno test results, and verified certification to ensure the claimed performance gains are realistic and legal for your specific application.

Emissions Laws and Certifications

When discussing emissions compliance for catalytic converters, two primary regulatory bodies come into play:

EPA (Environmental Protection Agency): The EPA sets federal emissions standards that all vehicles must meet nationwide.
CARB (California Air Resources Board): California has additional, stricter emissions standards enforced by CARB. Several other states have also adopted these CARB regulations.

Reputable aftermarket catalytic converter manufacturers will identify if their products meet EPA or CARB certification requirements, ensuring legal operation in your region.

Comparing Aftermarket Catalytic Converters vs. OEM Converters

To help you make an informed decision, let’s compare aftermarket and OEM catalytic converters across various factors:

Factor	Aftermarket	OEM
Cost	Generally less expensive, though quality can vary greatly	It is more costly up front but consistent quality from the vehicle manufacturer
Performance	Some high-flow options may provide modest power gains	Optimized for emissions control, not outright performance
Efficiency	Variable, depending on the quality and precious metal loading	Designed to meet or exceed emissions standards for that specific vehicle
Installation	“Universal” fits may require modifications; direct-fit options simplify installation.	Designed as a direct replacement for that make and model, ensuring proper fitment
Longevity	Lifespan can vary based on materials and construction quality	Generally longer-lasting due to OEM-grade materials and engineering

In the above, we compare aftermarket and OEM catalytic converters across various factors, including cost, performance, efficiency, installation process, and longevity.

Emissions Laws on Aftermarket Catalytic Converters

While aftermarket catalytic converters can provide cost-effective alternatives, ensuring they comply with emissions regulations in your area is crucial. Failure to do so can result in legal consequences, such as fines or failing emissions tests.

The Environmental Protection Agency (EPA) sets federal emissions standards that all vehicles must meet nationwide. Additionally, some states, like California, have adopted stricter regulations enforced by the California Air Resources Board (CARB).

Reputable aftermarket catalytic converter manufacturers will indicate if their products meet EPA or CARB certification requirements. Verifying this certification before purchasing is essential to ensure legal operation in your specific region.

How to Decide Which Type of Converter Is Best for Your Vehicle and Budget

With a clear understanding of the pros, cons, and factors involved, you can make an informed decision on whether an aftermarket or OEM catalytic converter is the right choice for your specific situation:

Budget Constraints: If cost is the primary concern, a well-researched and certified aftermarket converter can be a viable option, especially for older vehicles.
Fitment: Verify the converter is designed for your specific vehicle (make, model, year, engine). Universal-fit converters exist but may require additional modifications.
Longevity and Reliability: OEM converters from the vehicle manufacturer may be safer for peace of mind and long-term durability, albeit at a higher upfront cost.
Material: Ceramic substrates are more common and affordable but can be less durable than metallic options. Metallic substrates (often stainless steel) offer better flow and heat resistance but are pricier.
Performance Goals: If you’re seeking modest power gains while remaining street-legal, a high-flow aftermarket performance converter, primarily for modified or high-performance vehicles, could be worth considering.
Emissions Compliance: Ensure any aftermarket converter you choose is certified as compliant with your region’s emissions regulations (EPA and/or CARB) to avoid potential legal issues.
Warranty: Reputable brands often offer warranties on their converters, providing peace of mind.

Ultimately, the decision should balance your budget, performance needs, and commitment to emissions compliance while considering your vehicle’s age and intended use.

FAQs Related To Non-OEM Catalytic Converters

Can I Install Any Aftermarket Catalytic Converter on My Vehicle?

No, you should only install an aftermarket converter specifically designed or certified for your vehicle’s make, model, and engine configuration. Using an incompatible converter can lead to issues and potential emissions violations.

Will An Aftermarket Catalytic Converter Void My Vehicle’s Warranty?

Installing an aftermarket catalytic converter could void your manufacturer’s warranty, especially if it contributes to the failure of other emissions components or is improperly installed. Check with your warranty provider and follow their guidelines.

How Long Do Aftermarket Catalytic Converters Typically Last?

The lifespan of an aftermarket catalytic converter can vary widely depending on the quality of materials, construction, and driving conditions. High-quality units from reputable brands may last several years, while lower-grade converters may fail prematurely.

Can I Use a “Universal” Catalytic Converter on My Vehicle?

While universal converters are available, they often require significant modifications for proper fitment, increasing installation complexity and costs. Direct-fit options designed specifically for your vehicle are generally preferable.

Do I Need to Make Any Adjustments After Installing an Aftermarket Catalytic Converter?

Sometimes, you may need to adjust the position of downstream oxygen sensors or reprogram the vehicle’s computer to accommodate the new converter. Consult a professional for guidance.

Can an Aftermarket Catalytic Converter Improve My Vehicle’s Performance?

Most standard aftermarket converters are designed for emissions compliance and may not significantly impact performance. However, high-flow performance converters can provide modest power gains by reducing exhaust restrictions.

How Can I Ensure an Aftermarket Catalytic Converter Is Emissions Compliant?

Depending on your location’s emissions regulations, look for converters clearly labeled as EPA or CARB-certified. Reputable manufacturers will prominently display this information.

Can I Clean or Repair a Clogged Aftermarket Catalytic Converter?

In most cases, cleaning or repairing a severely clogged or damaged catalytic converter is not recommended. Replacement is often the safer and more cost-effective option.

Will Installing an Aftermarket Catalytic Converter Affect My Vehicle’s Resale Value?

A high-quality aftermarket converter may not significantly impact resale value if properly installed and documented. However, lower-grade or improperly installed units could deter some buyers.

Can I Use Fuel Additives or Cleaners With an Aftermarket Catalytic Converter?

It’s generally advisable to avoid using fuel additives or cleaners with aftermarket converters, as they could potentially contaminate or damage the internal components. Consult the manufacturer’s recommendations.

How Do I Dispose of an Old Catalytic Converter?

Due to the presence of precious metals, catalytic converters should be disposed of responsibly, often through specialized recycling facilities. Check with your local regulations for proper disposal methods.

Can I Install an Aftermarket Catalytic Converter, or Should I Have a Professional Do It?

While some mechanically inclined individuals may be able to install an aftermarket converter themselves, it’s generally recommended to have a professional mechanic handle the installation. Proper fitment and adjustments are crucial for optimal performance and emissions compliance.

Is An Aftermarket Catalytic Converter Right for Me?

Aftermarket catalytic converters can provide cost-effective alternatives to their more expensive OEM counterparts. However, navigating this market requires caution and due diligence. Not all aftermarket units are created equal, with vast quality, construction, and emissions compliance disparities.

By thoroughly researching reputable brands, verifying certifications, and considering factors like material quality and installation complexity, you can make an informed choice that aligns with your vehicle’s needs and budget constraints. Remember, while cost savings are appealing, compromising emissions standards or facing potential warranty issues may negate any short-term financial benefits.

Approach aftermarket catalytic converter purchases with an open mind, but remain vigilant in ensuring your choice meets all legal requirements and performance expectations. Consulting experienced professionals can also guide you through the installation process and help maximize the lifespan of your new converter.

Deciding between a Third-party or OEM catalytic converter should balance your priorities, whether cost-effectiveness, performance gains, emissions compliance, or long-term reliability. With the right information and precautions, an aftermarket unit can be a viable solution for keeping your vehicle on the road while respecting environmental regulations.