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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 Overall The best all-around choice for most situations | PHILTOP Direct-Fit Catalytic Converter for Infiniti G37 and Related Models (EPA Compliant) |  |
| Best Quality Built to a higher standard if you want something more solid | A-Premium Left & Right Catalytic Converter Kit, Direct-Fit, EPA Compliant |  |
| Best Value The sweet spot between price and what you get | RILONH Front Catalytic Converters for Infiniti G37 3.7L (Left + Right) |  |
| Best budget The cheapest option that still gets the job done reliably | PHILTOP Catalytic Converter for Infiniti G37 (Left) |  |
| Highest Rated A top-rated pick with lots of positive feedback | RZOCARULE Catalytic Converter for Infiniti G35/G37 3.5L/3.7L (EPA Compliant) |  |
| Most popular A crowd favorite that many people choose with confidence | PHILTOP Catalytic Converter for Infiniti G37 (2009–2013) |  |
| Best Seller A high-volume bestseller chosen again and again | FOMIUZY 2" Universal High-Flow Catalytic Converter with O2 Port and Heat Shield |  |
1. PHILTOP Direct-Fit Catalytic Converter for Infiniti G37 and Related Models (EPA Compliant)
| Manufacturer | PHILTOP |
|---|---|
| Model | INFINITI G37 2009-2013 Catalytic Converter |
| Position | Left, Right |
| EPA Compliance | Yes |
This PHILTOP catalytic converter is a direct-fit replacement intended for Infiniti G37 and several related Nissan/Infiniti models; units come flange-to-flange with OE-style gaskets and hardware for bolt-on installation. In use it replaces a failed or clogged factory converter to restore emissions control, reduce abnormal exhaust noise from damaged internals, and recover drivability lost to excess backpressure. Notable features include a high-flow ceramic honeycomb designed to improve conversion efficiency and reduce backpressure, a stainless steel outer shell for corrosion and heat resistance, and EPA compliance for federal emissions states. Practical benefits are straightforward: most buyers should be able to install both left and right converters in a few hours without major modifications, and the included gaskets/hardware simplify fitment. Limitations are mixed fitment reports across model years and occasional quality-control issues with supplied hardware and hanger placement, so careful inspection and readiness to swap bolts or make minor adjustments is advisable. Some users needed welding or minor modifications to achieve a perfect fit on nonstandard or older chassis variants.
Best for: Buyers who want a balanced, factory-replacement style catalytic converter for an Infiniti G37 that restores emissions function and drivability without chasing premium performance parts; ideal for owners valuing a reasonable mix of cost, durability, and straightforward installation.
Less Ideal for: Owners seeking a guaranteed perfect bolt-on fit on every model year or those who want a premium OEM-level part with no chance of adjustment; also not for vehicles required to meet California emissions standards.
- EPA-compliant design suitable for federal-emissions vehicles
- High-flow ceramic substrate aimed at lowering backpressure and improving catalytic efficiency
- Stainless steel outer shell and welded connections for durability
- Flange-to-flange, bolt-on design with included gaskets and hardware for easier installation
- Some customers report imperfect fitment or misaligned hanger/bolt patterns requiring modification
- Included hardware and gaskets have inconsistent quality in some batches
Verdict: A practical, EPA-compliant direct-fit catalytic converter option for Infiniti G37 owners who want to restore emissions and exhaust flow with a durable stainless steel build.
2. A-Premium Left & Right Catalytic Converter Kit, Direct-Fit, EPA Compliant
| EPA Compliant | Yes |
|---|---|
| Vehicle Emissions | Federal Emissions |
| Position | Left & Right |
| Body Material | Stainless Steel |
| Inlet Type | 3 Bolt Welded Flange |
This A-Premium kit supplies both left and right direct-fit catalytic converters for select Infiniti and Nissan 3.5L and 3.7L engines, intended as a straight replacement when a factory-style unit fails or triggers emissions codes. Installation is typically a bolt-on swap using the included two-bolt gaskets and hardware for the exhaust outlets and a three-bolt welded flange inlet interface; the kit ships with gaskets and bolts for most exhaust connections. Stainless steel construction offers corrosion resistance and the EPA-compliant substrate keeps the vehicle within federal emissions specs outside restricted states. In practice the kit restores exhaust flow and quiets exhaust noise compared with a failed unit, but some buyers report occasional fitment variance and missing manifold-end gaskets, so expect to verify flange type and have basic exhaust tools on hand. Warranty support is provided for one year. For a performance-oriented Infiniti G37 owner this is a budget-friendly factory-style replacement that can get the car back to proper emissions and drivability, though it may require minor adjustments during installation.
Best for: Performance-oriented owners seeking a factory-style, direct-fit replacement to restore emissions compliance and drivability on Infiniti G37s without upgrading to a high-flow aftermarket racing unit.
Less Ideal for: Owners in states with stricter aftermarket emissions rules or buyers wanting a long-term high-flow performance converter should consider alternatives or confirm local legality before purchasing.
- Direct-fit left and right kit covers both banks for paired replacement
- Stainless steel body improves corrosion resistance compared with mild steel units
- EPA-compliant substrate for federal emissions jurisdictions
- Includes gaskets and bolts for exhaust outlet connections to simplify installation
- 1-year unlimited-mileage warranty provided by the brand
- Not legal for sale or use in California, Colorado, New York, and Maine due to state emissions laws
Verdict: A practical, factory-style left and right catalytic converter kit that restores emissions function and drivability on compatible Infiniti G37 models.
3. 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.
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. RZOCARULE Catalytic Converter for Infiniti G35/G37 3.5L/3.7L (EPA Compliant)
| Brand | RZOCARULE |
|---|---|
| Compatibility | Infiniti G35/G37 2007-2013 3.5L/3.7L |
| EPA compliance | Meets U.S. EPA criteria |
| Housing material | Stainless steel |
| Core type | Ceramic honeycomb matrix |
This RZOCARULE catalytic converter is a bolt-on, flange-to-flange replacement made for Infiniti G35 (VQ35HR) and G35/G37 2007–2013 3.5L/3.7L applications and similar Nissan models. It uses a stainless steel outer shell and an internal ceramic honeycomb matrix coated with catalytic materials to convert harmful exhaust gases while resisting heat and corrosion. Installation is straightforward for experienced DIYers or professional shops because it uses factory-style flanges and comes with gaskets and hardware. In real-world use it provides a free-flowing path that can restore exhaust function and clear emission-related check-engine codes after the vehicle ECU adapts. Buyers should note it is EPA-compliant but explicitly restricted from sale or use in certain states and some owners report fitment or sensor adaptation issues on some vehicles, so confirm exact fitment and expect an ECU relearn period after replacement.
Best for: Reliability-focused owners who prioritize restoring emissions function with a direct-fit replacement and want a factory-style, bolt-on unit they can install with a shop or competent DIYer.
Less Ideal for: Owners in states with stricter emissions laws or anyone who needs a guaranteed plug-and-play solution without any ECU relearn or fitment verification should consider an alternative.
- Vehicle-specific flange-to-flange design with included gaskets and hardware for easier installation
- Stainless steel outer shell resists rust and heat for longer service life
- High-flow ceramic honeycomb core designed to maximize catalytic surface area and reduce emissions
- EPA-compliant design intended to meet federal emissions criteria
- Not legal for sale or use in California, New York, or Maine emissions models
- Some buyers report fitment or sensor adaptation problems and possible persistent check-engine lights until ECU adapts
Verdict: A factory-style, EPA-compliant replacement catalytic converter built to restore emissions performance on Infiniti G35/G37 models.
6. 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.
7. FOMIUZY 2" Universal High-Flow Catalytic Converter with O2 Port and Heat Shield
| Brand | FOMIUZY |
|---|---|
| Model | 2inch |
| Inlet/Outlet | 2" |
| Exterior | Milled |
This FOMIUZY catalytic converter is a budget-minded universal front cat designed to replace a failed unit and clear P0420-style codes when fitment matches. It installs inline with 2" piping and includes a welded O2 bung so the sensor can be relocated downstream or reused, plus a stamped heat shield for thermal protection. The stainless/aluminized housing and a layered ceramic carrier aim to balance flow with catalytic surface area to reduce emissions and restore quiet running. In practice the unit is useful for risk-averse owners who want a straightforward repair: fit, tack-weld, then fully weld to seal as recommended. Limitations are that it is a universal part so exact pipe ID/OD can vary and may require minor piping work or adapters for a perfect fit on the G37 exhaust, and some users report longevity and emissions effectiveness can vary by engine and local regulations. Not legal for sale in certain states with stricter standards.
Best for: Risk-averse mainstream Infiniti G37 owners looking for an affordable repair that restores driveability and clears emissions-related codes without unnecessary complexity.
Less Ideal for: Owners in states with strict emissions certification requirements or owners who need a vehicle-specific certified catalytic converter for inspection compliance.
- Includes an O2 sensor port for correct sensor placement or reuse
- Stainless/aluminized body resists rust and is suitable for exhaust environments
- Designed for direct inline replacement with 2" piping to resolve P0420 faults
- Universal sizing may need pipe modification or adapters to fit G37 exhaust precisely
- Not compliant for sale in some states with strict emissions standards
Verdict: A low-cost, easy-to-install 2" universal catalytic converter option to get an Infiniti G37 back on the road and resolve common catalytic-related faults.
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.
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.
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.
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.
Explore More:
- Check out all Infiniti G37 parts & accessories
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