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Replacing a failing catalytic converter can restore engine responsiveness and reduce harmful exhaust emissions in your Infiniti G37. You want a unit that fits correctly, meets emissions standards, and holds up to daily driving demands. This guide covers our seven shortlisted catalytic converters for the Infiniti G37 and explains the evaluation criteria we used, including fitment accuracy, emissions performance, and build quality. Read on to understand the factors that matter and to quickly find options suited to your needs.
Looking for other parts? See all Infiniti G37 parts & accessories.
Top Picks at a Glance
| Best Reviewed A top-rated pick with lots of positive feedback | maXpeedingrods Front Catalytic Converter for Nissan Altima 2.5L |  |
| Most Popular A crowd favorite that many people choose with confidence | PHILTOP Catalytic Converter for Infiniti G37 (2009–2013) |  |
| Best Quality Built to a higher standard if you want something more solid | Walker CalCat 82614 Universal Catalytic Converter |  |
| Best Budget The cheapest option that still gets the job done reliably | PHILTOP Catalytic Converter for Infiniti G37 (Left) |  |
| Most Sold A high-volume bestseller chosen again and again | A-Premium Catalytic Converter Kit compatible with Toyota Corolla 2014–2019 1.8L |  |
| Best Value for Money The sweet spot between price and what you get | RILONH Front Catalytic Converters for Infiniti G37 3.7L (Left + Right) |  |
| Best Overall The best all-around choice for most situations | Walker CalCat 83508 Universal Catalytic Converter |  |
1. maXpeedingrods Front Catalytic Converter for Nissan Altima 2.5L
| Compatibility | Fit for Nissan Altima 2.5L 2007 – 2013 |
|---|---|
| EPA Compliance | Meets federal emissions standards (not CARB) |
This front catalytic converter is a direct-replacement emissions part intended to restore catalytic function and clear codes like P0420 when the original unit has failed. It installs in place of the factory front converter using the included gaskets and hardware and is described as matching the original mounting points so no major modifications are required. The internal honeycomb ceramic substrate is coated with precious metal catalysts to convert CO, HC, and NOx to less harmful gases, and the high-flow design aims to maintain engine breathing and fuel economy. Construction from stainless steel targets corrosion and heat resistance for longer service life under normal road conditions. Practical limitations include regional emissions restrictions that prevent use in certain states and the fact that long-term durability depends on installation and upstream engine condition. Fitment here is presented for Nissan Altima 2.5L models, so confirming flange and sensor locations for an Infiniti G37 is necessary before purchase for compatibility concerns.
Best for: A reliability-focused buyer who prioritizes restoring emissions compliance and steady day-to-day operation rather than performance upgrades; suited for owners who prefer a like-for-like replacement to clear codes and pass inspections.
Less Ideal for: Drivers seeking a performance-oriented or custom exhaust modification, or those who need a part explicitly approved for emissions-controlled states should look elsewhere.
- Direct-fit replacement intended to match factory mounting points for straightforward installation
- EPA compliant for federal emissions standards outside restricted states
- Stainless steel construction resists rust and high exhaust temperatures
- Honeycomb ceramic substrate with Pt, Rh, and Pd catalysts to restore pollutant conversion
- Not legal for use in some states with stricter emissions rules
- Product listing specifies Altima fitment so compatibility with Infiniti G37 is not guaranteed
Verdict A budget-friendly, stainless-steel front catalytic converter intended to restore emissions function for compatible vehicles but verify fitment for the Infiniti G37 before buying.
2. PHILTOP Catalytic Converter for Infiniti G37 (2009–2013)
| Fitment | Infiniti G37 2009-2013 |
|---|---|
| Material | Stainless steel |
| Catalyst type | Ceramic honeycomb high-flow |
| EPA status | EPA compliant |
This PHILTOP catalytic converter is built as a direct replacement for the Infiniti G37 (2009–2013) to restore emissions performance and engine smoothness. It uses a high-flow ceramic honeycomb substrate and a stainless steel shell with welded seams to resist corrosion and high heat. In practice it installs in place of the failed unit to clear P0420-style codes, reduce exhaust noise from a busted converter, and help the engine breathe closer to factory behavior. The high-flow design aims to preserve power and fuel economy compared with a clogged or damaged original. Installation may require a professional or a shop familiar with exhaust work since some buyers reported mismatched bends or missing factory heat-shield mounts on rare units, so check fit closely before finalizing. This EPA-compliant unit is intended for emissions-legal replacement outside of states that restrict aftermarket converters. It is a practical option when you need a replacement that balances emissions function and flow without upgrading to an aftermarket performance system.
Best for: Convenience-driven buyers who want a ready replacement to get their Infiniti G37 back to emissions compliance and normal operation with minimal shopping hassle.
Less Ideal for: Buyers seeking a guaranteed bolt-in, no-modification DIY part or those who need California or Colorado-compliant converters should look for vehicle-specific dealer or state-approved options.
- Direct-fit replacement aimed at Infiniti G37 2009–2013 for straightforward swap-in service
- High-flow ceramic substrate designed to improve exhaust flow and help restore engine performance
- Stainless steel construction with welded seams for corrosion and heat resistance
- EPA compliant for aftermarket emissions replacement where allowed
- Some units have reported flange/bend misalignment or missing heat-shield mounts requiring modification or professional installation
- Installation instructions are generic and may not be sufficient for DIY mechanics
Verdict A practical, high-flow replacement that restores emissions and performance for Infiniti G37s but may need careful fit verification or pro installation.
3. Walker CalCat 82614 Universal Catalytic Converter
| Material | Aluminum, Stainless Steel |
|---|---|
| CARB EO# | D-182-57 |
| OBD Compatibility | OBDII vehicles (1996+), non-OBD 1995 and older |
| Manufacturer | Tenneco (Walker) |
The Walker CalCat 82614 is a universal catalytic converter built for reliable emissions control and workshop installation. It uses a stainless-steel body with aluminized pipe and heat shields for corrosion resistance and includes a high-technology washcoat and OE-style catalyst coating to meet CARB requirements on OBDII vehicles. Installers will appreciate its expandable bushings and direct-fit intent that reduce fabrication time, though some vehicle-specific welding or pipe work may still be required for a precise fit. In use it clears fault codes and restores emissions control to pass smog checks when matched correctly to the vehicle. The converter is aimed at professional installers and experienced DIYers who can accommodate minor modifications. Expect a durable component that prioritizes regulatory compliance and consistent catalyst performance, but plan for shop time and potential additional parts to achieve factory-quality fit and mounting on the Infiniti G37 chassis if exact piping or brackets differ.
Best for: Performance-oriented buyers who prioritize regulatory-compliant emissions control and consistent catalytic efficiency and who are comfortable working with a shop or an experienced installer to adapt a high-quality universal unit to their vehicle.
Less Ideal for: Owners seeking a bolt-in, vehicle-specific factory-quality replacement with no fabrication should consider a model made specifically for the Infiniti G37 or an exact factory-replacement part instead.
- CARB-compliant design for emissions-regulated states
- Stainless-steel body with aluminized pipe and heat shields for durability
- High-technology washcoat and OE-style catalyst coating for consistent emissions performance
- Expandable bushings and near-direct-fit design that simplify installation for shops
- Universal design may require welding, trimming, or additional pipes/brackets for exact fit on the G37
- Not a vehicle-specific OEM replacement so mounting points or hangers may not match factory locations
Verdict A durable, CARB-compliant universal catalytic converter aimed at performance-focused buyers and shops, but expect some fabrication to achieve a factory-style fit on the Infiniti G37.
4. PHILTOP Catalytic Converter for Infiniti G37 (Left)
| Position | Left |
|---|---|
| Manufacturer | PHILTOP |
| Model | Catalytic Converter INFINITI G37 2008-2013 |
| Exterior | Machined |
This PHILTOP catalytic converter is an affordable factory-replacement style unit built for left-side fitment on Infiniti G37 3.5L models. It installs in place of the original converter using the supplied gaskets and hardware, so many DIYers and independent shops can bolt it in without modifying the exhaust. The unit uses a stainless steel/aluminized pipe body with a dual-layer ceramic carrier intended to improve flow and oxygen storage for emissions control and modest gains in drivability and fuel economy. It is EPA compliant for most states outside strict emissions jurisdictions. Buyers report solid welds and thick flanges that seal well, though heat shield brackets may require slight adjustment during installation and some alignment fiddling can add time. This is not a factory brand part, so finish and bracket fitment vary more than an Infiniti factory unit, but the converter fixes common P0420 symptoms at a fraction of OEM cost. Expect good value if you need a working, legal replacement and are comfortable with basic exhaust alignment work.
Best for: Budget-conscious Infiniti G37 owners who prioritize a working, legal replacement that restores emissions function without paying OEM prices.
Less Ideal for: Owners in states with strict aftermarket emissions rules or those who need perfect factory-fit and finish should consider dealer or factory-quality replacements.
- Made for left-side fitment on Infiniti G37 3.5L models for direct replacement
- Stainless steel/aluminized construction resists rust and uses a high-temp ceramic carrier for emissions performance
- Supplied gaskets and mounting hardware enable bolt-in installation without part modification
- EPA compliant for aftermarket use in many states
- May require minor adjustment of heat shield brackets and extra alignment time during install
- Not a factory-brand unit so fitment and finish can vary compared with OEM replacements
Verdict A cost-effective, EPA-compliant left-side replacement for Infiniti G37 owners who want to fix emissions issues without the OEM price.
5. A-Premium Catalytic Converter Kit compatible with Toyota Corolla 2014–2019 1.8L
| Vehicle Fitment | Toyota Corolla 2014–2019 L4 1.8L |
|---|---|
| EPA Compliant | Yes (federal emissions) |
| Inlet Type | 2 Bolt Welded Flange |
| Outlet Type | 2 Bolt Welded Flange |
| Mounting Hardware | Included |
This A-Premium catalytic converter kit is a bolt-on replacement intended for the Toyota Corolla 2014–2019 L4 1.8L sedan with federal emissions. It installs using 2-bolt welded flanges at inlet and outlet and includes mounting hardware, so a mechanic can swap it in without custom fabrication. The unit is listed as stainless steel construction and claims EPA compliance for federal-emissions vehicles, which helps restore emissions control and clear related check engine codes. Practical benefits include a one-year unlimited-mileage guarantee and straightforward fitment for Corolla owners needing a direct replacement. Limitations to consider are regulatory restrictions: EPA-compliant converters from this listing cannot be sold or installed in certain states under some conditions, so state emissions rules must be checked before purchase. There are mixed user reports about surface corrosion on the mid pipe, so long-term corrosion resistance may vary depending on local road and climate exposure.
Best for: Risk-averse mainstream buyers seeking a direct factory-replacement catalytic converter for a Corolla 2014–2019 who prioritize straightforward fitment and short-term warranty protection.
Less Ideal for: Buyers in states with restrictive aftermarket converter rules or those needing a converter specifically certified for California or other restricted-state emissions should look for compliant alternatives.
- Direct-fit design with 2-bolt welded flanges and included mounting hardware for straightforward installation
- Designed for Toyota Corolla 2014–2019 1.8L federal-emissions vehicles, simplifying part selection
- Stainless steel body construction aimed at durability compared with lower-grade materials
- One-year unlimited-mileage guarantee provides short-term coverage for defects
- Not eligible for sale or installation in some states under specific local regulations
- Customer reports indicate possible surface rusting on the mid pipe in real-world use
Verdict A practical, direct-fit replacement for Corolla 2014–2019 federal-emissions cars that simplifies installation but may be restricted in some states and has mixed long-term corrosion feedback.
6. RILONH Front Catalytic Converters for Infiniti G37 3.7L (Left + Right)
| Fitment | Infiniti G37 3.7L 2008-2013 |
|---|---|
| Placement on Vehicle | Front, Left and Right |
| Substrate Material | Ceramic |
| Heat Shield Material | Stainless Steel |
This pair of front catalytic converters replaces the left and right units on the Infiniti G37 3.7L and ships with gaskets and bolts for a one-stop install. They use a ceramic substrate and stainless steel heat shield and housing, which helps longevity and resists corrosion compared with thin-sheet aftermarket parts. Typical use is a direct replacement after failure or theft when the check engine light or emissions test failure requires a new unit; installation is a standard exhaust job and many buyers report completing both sides in about an hour when working under the car. The kit is EPA compliant for most states but not CARB compliant so it cannot be used in California and a few other states. Practical benefits include included hardware and a factory-style fit that usually clears sensors and bolts without modification. The main limitations are regulatory restrictions preventing use in CARB states and the absence of a stated mileage or sound warranty, so long-term performance depends on driving conditions and installation quality.
Best for: A practical optimizer looking for a cost-effective, near-factory replacement that minimizes installation hassle and gets the G37 back on the road without custom work.
Less Ideal for: Buyers in CARB-regulated states or those who need a certified CARB-compliant converter should look for a compliant alternative; also avoid if you require a stated long-term warranty.
- Designed as a direct front-left and front-right replacement for Infiniti G37 3.7L for straightforward fitment
- Stainless steel housing and heat shield for improved durability and corrosion resistance
- Includes installation accessories such as gaskets and bolts to avoid reusing old parts
- Not CARB compliant so it cannot be legally installed in California and other restricted states
- No explicit long-term warranty or mileage guarantee provided by the listing
Verdict A practical, ready-to-install front converter pair for the G37 that balances durability and value but is not CARB compliant.
7. Walker CalCat 83508 Universal Catalytic Converter
| CARB EO | D-182-69 |
|---|---|
| Vehicle coverage | For OBDII vehicles, 1996 and newer |
| Construction | Stainless-steel body with aluminized pipe and heat shields |
| Model number | 83508 |
The Walker CalCat 83508 is a replacement catalytic converter built for emissions compliance on OBDII vehicles and intended for professional installation or modification. It uses a factory-style washcoat on a substrate to provide consistent catalyst performance and carries CARB EO D-182-69 for states that require California-compliant converters. The stainless-steel body, aluminized pipe and heat shields improve durability against road corrosion, and expandable bushings and a universal inlet/outlet design let shops adapt the unit to a range of exhaust layouts. For an Infiniti G37 buyer focused on a reliable emissions fix, this unit offers the materials and certification to pass smog when fitted properly. Expect to need clamps, reducers, or welding for a correct fit and occasional fabrication work to match factory piping; the universal approach means extra labor compared with a vehicle-specific, bolt-in converter. Some users report long-term durability is mixed, so proper installation and correct oxygen sensor placement remain important for lasting service.
Best for: Balanced buyers who want a certified, emissions-focused replacement for an Infiniti G37 and are willing to pay for a shop installation or minor fabrication to ensure a proper fit and smog-ready performance.
Less Ideal for: Buyers seeking a guaranteed bolt-in, DIY plug-and-play converter specifically tailored to the Infiniti G37 or those unwilling to arrange professional installation should consider a vehicle-specific factory-quality replacement instead.
- CARB-compliant for states that require California-spec converters
- Stainless-steel body with aluminized pipe and heat shields for improved corrosion resistance
- Factory-style catalyst coating process aimed at consistent emissions performance
- Universal inlet/outlet and expandable bushings allow shops to adapt the unit to different exhaust layouts
- Universal design may require welding, reducers, or clamps rather than offering a bolt-on fit for the G37
- Installation may need professional exhaust shop work to ensure correct oxygen sensor placement and leak-free joints
- Some user reports indicate variable long-term durability on high-mileage vehicles
Verdict A CARB-compliant, durable universal converter that can get an Infiniti G37 smog-ready when professionally adapted, but it is not a direct bolt-on solution.
Choosing the Right Infiniti G37 Catalytic Converter: Key Factors to Consider
Fitment and Mounting Compatibility
Correct physical fitment is the foundation of a successful replacement. A catalytic converter must match the Infiniti G37s factory mounting points, pipe diameters, and overall length so installation does not require cutting, welding, or improvised adapters. Poor fitment can lead to exhaust leaks, increased noise, or stress on adjacent components.
When fitment is right, installation time is shorter and the chance of future failure from vibration or exhaust movement is lower. Confirm the converter aligns with oxygen sensor ports and flange types to preserve sensor function and avoid triggering diagnostics.
Emissions Conversion Efficiency
The primary role of the catalytic converter is to convert hydrocarbons, carbon monoxide, and nitrogen oxides into less harmful gases. Substrate material, cell density, and the washcoat chemistry all influence how effectively the unit reduces emissions under real-world conditions.
Higher conversion efficiency helps the vehicle meet emissions inspections and can prevent driveability issues related to poor combustion byproducts. Look for specifications or test data that indicate robust conversion across typical operating temperatures for the G37.
Durability and Heat Resistance
Catalytic converters are exposed to high temperatures and corrosive exhaust gases, so housing strength and thermal stability matter. A durable shell, quality internal substrates, and secure mounting help resist cracking, collapse, and premature degradation caused by thermal cycling.
Heat tolerance also affects longevity under heavy use, such as extended high-speed driving or towing. Materials and manufacturing that minimize hot spots and withstand thermal expansion will reduce the chance of catastrophic failure and ensure consistent emissions control.
Backpressure and Engine Performance
While the converter must restrict enough flow to facilitate chemical conversion, excessive backpressure can reduce engine efficiency and throttle response. Choose a design that balances conversion efficiency with adequate exhaust flow for the Infiniti G37s engine characteristics.
Manufacturers often specify flow ratings or cell densities that help predict how a unit will affect performance. Matching the converter to the engine's exhaust flow helps maintain horsepower and fuel economy while still meeting emissions goals.
Sensor Compatibility and Placement
Oxygen sensors play a central role in engine control and emissions monitoring. The catalytic converter must provide correct sensor bung locations and thread sizes so the vehicle's factory sensors fit without modification.
Proper sensor placement ensures accurate readings for the engine control unit, reducing the risk of a check engine light or poor air-fuel control. Verify the converter supports upstream and downstream sensor positions used on the Infiniti G37.
Warranty and Manufacturer Support
A solid warranty and accessible manufacturer support indicate confidence in product durability. Warranties that cover structural integrity and substrate failure give you recourse if the converter degrades prematurely.
Good documentation and customer support make installation and any potential returns or claims smoother. Consider the length and conditions of coverage when weighing options, especially if you plan to keep the car long term.
FAQ
How do I know if the catalytic converter is failing on my Infiniti G37?
Common signs often include reduced engine performance, a rotten egg smell from the exhaust, or unusual exhaust odor. You may also see the check engine light catalytic converter or related diagnostic codes. A mechanic can inspect backpressure and sensor readings to help confirm a diagnosis.
Can I replace the catalytic converter myself on an Infiniti G37?
How to replace catalytic converter procedures depend on your mechanical skill and tools. Many converters bolt into the exhaust, making replacement straightforward for someone with experience, while rusted fasteners or tight clearances can complicate the job. If you are uncertain, professional installation reduces risk of leaks or improper fitment.
Will installing a new catalytic converter affect emissions testing for my Infiniti G37?
A properly fitted converter with adequate emissions conversion efficiency should improve exhaust emissions catalytic converter results and help the vehicle meet inspection standards. Ensure the unit provides the correct substrate and is compatible with the G37s sensor arrangement to prevent test failures.
What causes catalytic converter failure signs on the Infiniti G37?
Failure signs often stem from prolonged exposure to contaminants, oil or coolant leaks into the exhaust, overheating, or physical damage. Repeated unburned fuel entering the converter can overheat the substrate, while impact damage can crush internal components. Addressing underlying engine issues helps prevent repeat failures.
Do I need to worry about CAT converter fitment when shopping for a replacement?
Yes. CAT converter fitment is critical to avoid exhaust leaks, preserve sensor function, and ensure straightforward installation. Verify flange types, pipe diameters, sensor port locations, and mounting points before purchasing to minimize installation complications.
How We Chose the Best Infiniti G37 Catalytic Converter
We focused on parts that are specifically designed to fit the Infiniti G37 and meet emissions control expectations. Key evaluation criteria included physical fitment accuracy to factory mounting points and dimensions, catalytic substrate type and washcoat formulation for emissions conversion efficiency, and construction quality of the housing and flanges to resist corrosion and leakage. We also considered heat tolerance and backpressure characteristics to avoid negatively impacting engine performance, plus warranty coverage and manufacturer support as indicators of long-term reliability. We excluded universal or generic converters that require extensive modification to install, units without documented emissions certification where applicable, and parts with inadequate hardware or unclear fitment specifications. The list emphasizes components that balance reliable emissions control with durable construction and straightforward installation for this specific vehicle.
Our full evaluation process is outlined in our review methodology.
Conclusion
Prioritize correct fitment, proven emissions conversion, and durable construction when choosing a catalytic converter for the Infiniti G37. Balancing acceptable backpressure with effective substrate chemistry will preserve engine performance while meeting emissions requirements. Also consider sensor compatibility and warranty terms to reduce future hassles. Address any engine issues that contributed to the original failure before installation to maximize the lifespan of the replacement.
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