Catalytic Converter for Toyota Sienna (2004-2010) 3.3L 3.5L Rear

Direct-Fit Rear Catalytic Converter for 2004-2010 Toyota Sienna

What it Does: The direct-fit rear catalytic converter replaces the clogged or degraded factory underfloor unit on the 2004-2010 Toyota Sienna to restore correct exhaust backpressure, eliminate emissions-related trouble codes, and reduce toxic tailpipe emissions.

The Stock Toyota Sienna Catalytic Converter Degradation

As the second-generation XL20 platform ages, the factory rear catalytic converter frequently succumbs to thermal fatigue and internal washcoat depletion. High-mileage 3MZ-FE and 2GR-FE V6 engines can suffer from minor oil consumption and rich-running cycles, causing carbon deposits to foul the factory ceramic substrate. This thermal breakdown and physical soot loading restrict exhaust gas velocity, elevating backpressure, bogging down acceleration, and triggering persistent P0420/P0430 diagnostic trouble codes. Furthermore, road brine and thermal cycling routinely corrode the factory exhaust flanges, causing persistent exhaust leaks.

The Engineering Solution

This replacement rear converter assembly is built with a heavy-gauge 409 stainless steel outer casing engineered to withstand harsh road conditions and continuous thermal expansion. Internally, a high-efficiency ceramic honeycomb substrate delivers optimal surface area for noble metal catalysts (platinum, palladium, and rhodium) to cleanly convert unburnt hydrocarbons, carbon monoxide, and NOx. Featuring thick, OE-spec laser-cut flanges, accurate oxygen sensor bungs, and complete installation hardware, this unit bolts directly up to factory hangers without custom cutting or welding.

Technical Specifications

Compatibility

• 2004-2006 Toyota Sienna 3.3L V6 (CE, LE, XLE, XLE Limited)
• 2007-2010 Toyota Sienna 3.5L V6 (CE, LE, XLE, Limited)
• FWD and AWD configurations (Rear / Underfloor position)

Frequently Asked Questions

Does this fit the XL20 Sienna?
Yes, this is a direct fit for the 2004-2010 Toyota Sienna equipped with the 3MZ-FE or 2GR-FE engine in the rear underfloor position.

Will this resolve catalyst efficiency DTC codes like P0420?
Yes, provided upstream misfires and air-fuel ratio sensor faults are resolved, the fresh washcoat will restore catalytic efficiency and turn off the CEL.

The Toyota Durability Standard

Built to handle the extended family hauling and long-distance miles demanded of the Toyota Sienna, this converter provides robust structural integrity and factory exhaust clearance for reliable daily service.