P2442 on Subaru
Secondary Air Injection System Switching Valve Stuck Open (Bank 2)
P2442 on Subaru vehicles indicates secondary air injection system switching valve stuck open (bank 2). Au7o has documented this code across 1 Subaru model — most commonly on WRX STI. This is an emissions-system code, and it's the opposite condition of P2443. The secondary air injection system briefly pumps fresh air into the exhaust after a cold start so the catalytic converter warms up and cleans pollutants more quickly. P2442 means the switching (changeover) valve on Bank 2 — the cylinder bank that does not contain cylinder 1 — appears stuck in the open position, allowing air to flow when it shouldn't. The computer detects this through pressure/flow sensing or by seeing an oxygen-sensor reading that's leaner than expected when the air pump should be off. It's an emissions and inspection issue, not a drivability emergency. Typical repair costs on Subaru range from $600 to $2,200, depending on the specific model and root cause.
Common Causes of P2442
- •Switching/changeover valve stuck or sticking open (Bank 2)
- •Carbon, debris or corrosion holding the valve open
- •Failed vacuum or electric solenoid controlling the valve
- •Vacuum hose leak, crack or wrong routing to the valve
- •Leaking or failed check/combination valve
- •Wiring or connector fault to the control solenoid
P2442 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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What does P2442 mean on Subaru?▼
P2442 stands for "Secondary Air Injection System Switching Valve Stuck Open (Bank 2)." This is an emissions-system code, and it's the opposite condition of P2443. The secondary air injection system briefly pumps fresh air into the exhaust after a cold start so the catalytic converter warms up and cleans pollutants more quickly. P2442 means the switching (changeover) valve on Bank 2 — the cylinder bank that does not contain cylinder 1 — appears stuck in the open position, allowing air to flow when it shouldn't. The computer detects this through pressure/flow sensing or by seeing an oxygen-sensor reading that's leaner than expected when the air pump should be off. It's an emissions and inspection issue, not a drivability emergency. On Subaru specifically, this code is documented across 1 model.
What causes P2442 on Subaru vehicles?▼
Common causes on Subaru: Switching/changeover valve stuck or sticking open (Bank 2), Carbon, debris or corrosion holding the valve open, Failed vacuum or electric solenoid controlling the valve, Vacuum hose leak, crack or wrong routing to the valve, Leaking or failed check/combination valve. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2442 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 P2442 documented?▼
Au7o has documented P2442 on 1 Subaru model: WRX STI.