Catalytic Converter for Subaru Forester (2009-2010) 2.5L

Direct-Fit Stainless Catalytic Converter for 2009-2010 Subaru Forester

Direct Replacement Emissions Solution: Restores exhaust scavenging efficiency and eliminates downstream P0420 catalytic efficiency codes on naturally aspirated 2.5L Boxer engines.

The Stock Forester Catalyst Degradation

The factory rear catalytic converter on SH-generation Foresters faces relentless thermal cycling from the EJ253 Boxer layout. Over time, recurring oil vapor carryover through the PCV system and rich combustion events erode the internal precious metal washcoat. This causes cell sintering, substrate fracturing, and carbon clogging. The resulting increase in exhaust backpressure chokes engine scavenging, elevates cylinder head temperatures, and triggers continuous P0420 diagnostic trouble codes while disrupting closed-loop fuel trim adjustments.

The Engineering Solution

Fabricated with a corrosion-resistant stainless steel outer casing, this converter withstands high-temperature exhaust pulses and harsh underbody environments. Internally, a dense ceramic honeycomb substrate maximizes exhaust surface contact to efficiently convert hydrocarbons, carbon monoxide, and NOx without restricting flow dynamics. Thick, precision-machined flanges bolt directly to the stock intermediate pipe and tailpipe, sealing flush with the supplied replacement gaskets and hardware to eliminate exhaust leaks.

Technical Specifications

Compatibility

• 2009 Subaru Forester 2.5L H4 - Rear Placement
• 2010 Subaru Forester 2.5L H4 - Rear Placement

The Subaru Reliability Standard

Engineered to preserve factory Boxer backpressure dynamics and clear diagnostic emissions monitors, this bolt-on assembly delivers clean exhaust flow and reliable off-pavement performance without triggering check-engine lights.