P2443 on Subaru
Secondary Air Injection System Switching Valve Stuck Closed (Bank 2)
P2443 on Subaru vehicles indicates secondary air injection system switching valve stuck closed (bank 2). Au7o has documented this code across 1 Subaru model — most commonly on WRX STI. This code is part of your car's emissions system. The secondary air injection system pumps fresh air into the exhaust right after a cold start to help the catalytic converter heat up and burn off pollutants faster. P2443 means the switching (changeover) valve that controls this airflow on Bank 2 — the side of the engine that does NOT contain cylinder 1 on a V-style engine — appears stuck in the closed position, so the expected air isn't reaching the exhaust. The computer detected this either by monitoring air pressure/flow or by seeing the wrong oxygen-sensor response during the cold-start air pump test. It's an emissions and inspection concern rather than something that will strand you. Typical repair costs on Subaru range from $600 to $2,200, depending on the specific model and root cause.
Common Causes of P2443
- •Stuck or seized secondary air injection switching/changeover valve (Bank 2)
- •Carbon, moisture or rust buildup inside the valve or air passages
- •Failed vacuum or electric solenoid that operates the switching valve
- •Disconnected, cracked or collapsed vacuum hose to the valve
- •Failed or weak secondary air injection pump
- •Wiring or connector fault to the valve/solenoid
- •Clogged combination valve or check valve preventing airflow
P2443 on Subaru by Model
Subaru WRX STI(1 issue)
- Air Injection System (Secondary Air Pump/Valves) Failure (P0410/P244x)2008-2014
Subaru WRX STI models equipped with the EJ257 and secondary air injection commonly develop failures of the air pump and/or the air switching valves, often due to moisture intrusion and internal corrosion that causes the valves to stick. Owners typically see a check engine light with cold-start drivability changes and may fail emissions/inspection due to stored air injection codes. This issue is widely documented in owner reports and Subaru service information/TSBs covering secondary air injection diagnostics and component replacement.
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View P2443 across all makes →Frequently Asked Questions
What does P2443 mean on Subaru?▼
P2443 stands for "Secondary Air Injection System Switching Valve Stuck Closed (Bank 2)." This code is part of your car's emissions system. The secondary air injection system pumps fresh air into the exhaust right after a cold start to help the catalytic converter heat up and burn off pollutants faster. P2443 means the switching (changeover) valve that controls this airflow on Bank 2 — the side of the engine that does NOT contain cylinder 1 on a V-style engine — appears stuck in the closed position, so the expected air isn't reaching the exhaust. The computer detected this either by monitoring air pressure/flow or by seeing the wrong oxygen-sensor response during the cold-start air pump test. It's an emissions and inspection concern rather than something that will strand you. On Subaru specifically, this code is documented across 1 model.
What causes P2443 on Subaru vehicles?▼
Common causes on Subaru: Stuck or seized secondary air injection switching/changeover valve (Bank 2), Carbon, moisture or rust buildup inside the valve or air passages, Failed vacuum or electric solenoid that operates the switching valve, Disconnected, cracked or collapsed vacuum hose to the valve, Failed or weak secondary air injection pump. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2443 on a Subaru?▼
Repair costs on Subaru range from $600 to $2,200, depending on the specific model and root cause.
Which Subaru models have P2443 documented?▼
Au7o has documented P2443 on 1 Subaru model: WRX STI.