Catalytic Converter for Infiniti FX35 (2003-2008) 3.5L

Direct-Fit Stainless Catalytic Converter Pair for 2003-2008 Infiniti FX35 (S50)

What it Does: This direct-fit catalytic converter pair bolts onto the 2003-2008 Infiniti FX35 (S50) VQ35DE 3.5L V6 to restore exhaust emissions scrubbing and eliminate catalyst efficiency codes.

The Stock Infiniti FX35 Catalytic Converter Failure

On the S50 chassis with the VQ35DE 3.5L V6, dual factory converters sit close to the exhaust manifolds and endure severe thermal cycling. Repeated heat soak, age-related oil consumption, or ignition misfires degrade the precious-metal washcoat and fracture the ceramic monolith. As oxygen storage drops, downstream sensors trigger P0420 or P0430 codes while detached core chunks rattle inside the housing and restrict exhaust scavenging.

Common Symptoms of a Failing OEM Catalytic Converter

• Check Engine Light / DTCs: P0420 or P0430 codes triggered when rear O2 sensor readings mirror upstream exhaust flow.
• Substrate Rattle: Metallic clattering under the floorpan caused by a fractured ceramic core inside the converter shell.
• Backpressure & Emissions Failure: Sluggish throttle response, sulfur odor, and failed OBD-II readiness or smog checks.

The Direct-Fit Stainless Catalytic Converter Solution

Replacing both banks with this 2-piece stainless assembly restores balanced flow on the VQ35DE V6 without cutting or welding. Each converter pipe uses an 8-inch by 5-inch corrosion-resistant housing containing a dual-stage ceramic honeycomb substrate coated in precious metals to convert HC, CO, and NOx. Precision-welded factory flanges and integrated post-catalyst O2 sensor bungs ensure OE bolt-on geometry and leak-free sealing.

What's Included

• 2 x Catalytic Converter Pipes (Pair)
• 2 x 2-Bolt Flange Gaskets
• 2 x Ring Gaskets
• Bolts, Nuts, and Washers

Technical Specifications

Compatibility

• 2003 Infiniti FX35 (3.5L V6)
• 2004 Infiniti FX35 (3.5L V6)
• 2005 Infiniti FX35 (3.5L V6)
• 2006 Infiniti FX35 (3.5L V6)
• 2007 Infiniti FX35 (3.5L V6)
• 2008 Infiniti FX35 (3.5L V6)

Frequently Asked Questions & Fitment Warnings

Does this fit the S50 FX35?

Yes. This is a direct fit for the 2003-2008 Infiniti FX35 equipped with the VQ35DE engine. Excludes the FX45 4.5L V8, 2009+ FX35, and vehicles registered in CA, NY, CO, or ME (EPA Federal, not CARB approved).

Will this clear P0420/P0430 codes, and are O2 sensors included?

Yes, when caused by worn converters; O2 sensors are not included. Transfer functional sensors or install new units into the post-cat ports, and check for exhaust leaks before clearing P0420/P0430.

Are gaskets and hardware included for installation?

Yes. Both flange gaskets, ring gaskets, bolts, nuts, and washers are included; soak old studs with penetrating oil and torque fasteners evenly on a cool exhaust.

The Infiniti Performance Standard

Engineered for the S50 platform, this dual-pipe set restores smooth scavenging and crisp throttle response on the VQ35DE V6 while keeping your OBD-II monitors ready.