P2442: AIR System Switching Valve Stuck Open (Bank 2)

P2442 is the stuck-open fault of the bank 2 secondary air valve: with the pump on and the valve commanded shut, air still passes, or exhaust flows back towards the pump. Lexus applies it to the 2010–2013 GX 460 with the 1UR-FE engine; bulletin L-SB-0028-14 replaces the bank 2 air switching valve and the pump, because a damaged pump filter sheds debris. Toyota's T-SB-0033-17 does the same for the 2012 Tacoma 4.0L V6 (1GR-FE) when P2440, P2442 or P2445 are stored. Subaru lists P2442 for the 2011–2015 WRX STI. Hot exhaust gas passing an open path can melt hoses and ruin the pump, so the fault should not be left for long. Bank 1 uses P2440, the stuck-closed counterpart is P2443.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• Check engine lamp after a cold start
• Pump noise or later pump failure
• Melted or brittle air hoses

Most likely causes

• Bank 2 valve held open by debris from the pump filter
• Valve seat or diaphragm damaged by heat or condensate
• Actuator does not close the valve

What to check, in order

Start with the simplest. You can tick off each step.

1. Listen for the pump running during a cold start
2. Check the continuity of the wire between the component and the control module.
3. Check the fuse and relay
4. Inspect the hoses and valve for moisture or carbon
5. Run the actuator test with the scanner

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P2442 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 4: Emissions
• 42: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2442?

Yes, you can keep driving, though it should be repaired: the car pollutes more at startup and may not pass an inspection.

What causes code P2442?

The most common causes are: bank 2 valve held open by debris from the pump filter; valve seat or diaphragm damaged by heat or condensate; actuator does not close the valve.

Related codes

• P2440AIR System Switching Valve Stuck Open (Bank 1)
• P2443AIR System Switching Valve Stuck Closed (Bank 2)
• P2445AIR System Pump Stuck Off (Bank 1)
• P0492AIR System Insufficient Flow Bank 2

Sources

• static.nhtsa.gov: SB 10061695 2273
• static.nhtsa.gov: MC 10141580 9999
• static.nhtsa.gov: MC 10235914 9999

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.