Guide to Replacing Catalytic Converters on a 2008-2012 INFINITI EX35
Facing a check engine light with codes P0420 or P0430? Here is what you need to know before replacing the catalytic converters on your EX35.
- The INFINITI EX35 has two catalytic converters integrated with the exhaust manifolds, making replacement a complex and labor-intensive job.
- Always diagnose and fix the root cause of converter failure (e.g., misfires, oil leaks) before installing new parts to avoid repeat damage.
- You must purchase a converter that is compliant with your state's laws (Federal EPA or CARB).
- Aftermarket brands like MagnaFlow offer a reliable, cost-effective alternative to expensive OEM parts, but ensure you select a direct-fit model for your EX35.
Understanding Catalytic Converter Failure on Your EX35
If your catalytic converter is failing, it's almost always because of another problem with your vehicle. The VQ-series engine in your EX35 is robust, but issues like engine misfires from bad ignition coils or spark plugs can send unburned fuel into the exhaust. This raw fuel can overheat and melt the delicate honeycomb structure inside the converter, causing a blockage. Similarly, engine oil or coolant leaks can contaminate the catalyst, making it ineffective. Before you replace the converters, it is critical to diagnose and fix the root cause, or you will likely ruin the new parts as well.
Symptoms of a Failing Catalytic Converter
The signs of a bad catalytic converter can range from subtle to severe. Being aware of them can help you address the issue before it causes more damage.
- Check Engine Light: The most common sign is a check engine light with codes P0420 (Catalyst System Efficiency Below Threshold Bank 1 🎬 Watch this breakdown of what P0420 and P0430 codes actually mean.) or P0430 (Bank 2).
- Reduced Engine Performance: A clogged converter restricts exhaust flow, which can make your EX35 feel sluggish and slow to accelerate.
- Rattling Noise: If the internal honeycomb structure breaks apart, you may hear a rattling sound from underneath the vehicle, especially on startup or when accelerating.
- Rotten Egg Smell: A failing converter may not properly process the sulfur in gasoline, leading to a distinct rotten egg (sulfur) smell from the exhaust.
An Important Note on Your EX35's Converters
The 2008-2012 INFINITI EX35 has two catalytic converters that are integrated directly into the exhaust manifolds. This means they are not a simple bolt-on part underneath the car; they are attached directly to the engine's cylinder heads. This design makes replacement a more labor-intensive and costly job compared to vehicles with underbody converters.
Choosing the Right Aftermarket Catalytic Converter
When replacing your converters, you have a choice between OEM (Original Equipment Manufacturer) and aftermarket parts. OEM converters are expensive, often costing over $1,300 per side. Aftermarket parts offer a more affordable solution, but quality can vary. It is crucial to choose a reputable brand to ensure a proper fit and avoid a recurring check engine light.
Aftermarket Brand Tiers
- Premium Brands (MagnaFlow): MagnaFlow is a well-regarded brand that offers both Federal (EPA) and California (CARB) compliant converters. They are known for high-quality construction, often using stainless steel, and are designed to match OEM performance, making them a reliable choice to keep the check engine light off.
- Standard Brands (AP Exhaust, Eastern Catalytic, Davico): These brands provide a good balance of quality and value. They are a solid choice for drivers who need a reliable replacement without the higher cost of premium brands. Forum discussions suggest that brands like Eastern Catalytic are a decent budget-friendly option.
- Value Brands (Evan Fischer): These are typically the most affordable options. While they can get your vehicle back on the road and pass an emissions test, they may not have the same longevity or perfect fit as higher-priced alternatives.
Federal EPA vs. CARB Compliance
You MUST buy a converter that is legal in your state. California, New York, Colorado, and Maine require CARB-compliant converters, which are more expensive due to stricter standards and more precious metals. All other states generally allow the use of Federal EPA-compliant converters. Installing a non-compliant converter can result in a failed emissions test and fines. Always verify your state's requirements before purchasing.
Estimated Costs for Replacement
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Converter (per side) | $120 - $578 |
| New OEM Converter (per side) | $1,350 - $1,650+ |
| Shop Labor | $400 - $800+ |
| Total Aftermarket Replacement (Both Sides) | $640 - $1,950+ |
| Total OEM Replacement (Both Sides) | $3,100 - $4,100+ |
*Costs are estimates and can vary based on your location, the specific parts chosen, and your mechanic's labor rates. The EX35 has two converters.
Frequently Asked Questions
Do I have to replace both catalytic converters at the same time?
Not necessarily. If only one converter has failed (e.g., you only have a P0420 code and not a P0430), you can replace just the failed side. However, since both converters are the same age and have been subjected to the same conditions, it's common for the second one to fail soon after the first. If your budget allows, replacing them in pairs can save you on future labor costs.
Why did my original catalytic converter fail?
Converters usually fail due to an external problem. 🎬 Learn about the root causes that lead to converter failure. Common causes include a rich fuel mixture, engine misfires, burning oil or coolant, or failed oxygen sensors. It is critical to fix the underlying issue before installing a new converter to prevent repeat failure.
Can I clean my catalytic converter instead of replacing it?
While some fuel additives claim to clean converters, they are generally ineffective for a converter that is physically damaged, melted, or clogged. These products might temporarily help with minor carbon buildup but will not fix a converter that has 🎬 See if a simple cleaning method can clear your engine codes. triggered a P0420 or P0430 code due to catalyst degradation. Replacement is the only permanent solution for a failed converter.
Are there any recalls for the 2008-2012 EX35 catalytic converter?
A search of the National Highway Traffic Safety Administration (NHTSA) database did not show any specific recalls for the catalytic converters on the 2008-2012 INFINITI EX35. Recalls are typically issued for safety defects, and converter failure is generally considered a wear-and-tear or emissions-related component issue.
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Technical Specifications
OEM Part Numbers: B08B3-1BA0B B08B2-1BA0B B08B3-1BA0A
The 2008-2012 INFINITI EX35 is equipped with a 3.5L VQ35HR V6 engine. It uses two catalytic converters, one for each cylinder bank (Bank 1 and Bank 2), which are integrated into the exhaust manifolds.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI EX35:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Understanding Catalytic Converter Failure on Your EX35
- Symptoms of a Failing Catalytic Converter
- An Important Note on Your EX35's Converters
- Choosing the Right Aftermarket Catalytic Converter
- Aftermarket Brand Tiers
- Federal EPA vs. CARB Compliance
- Estimated Costs for Replacement
- Frequently Asked Questions
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