P2442: How to Diagnose & Fix — Secondary Air Injection System Switching Valve Stuck Open (Bank 2)
7 vehicles · 3 makes · $100-$3,500 repair
How to diagnose and fix P2442: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Toyota Sequoia · 2005–2009
The 4.7L 2UZ-FE's secondary air injection system fails due to corroded air switching valves (ASVs) and seized air pumps. Moisture enters the system and corrodes internal components. Causes check engine light with P2440/P2442 codes.
Common Symptoms
- Check engine light with P2440 or P2442 codes
- Rough idle on cold start
- Ticking or buzzing noise from air pump on startup
- Failed emissions testing
How to Fix
Replace air switching valves (Toyota 25710-50032 and 25710-50042, which supersede 25710-50030/25710-50040) and air injection pump (Toyota 17610-0C010) if seized. Many owners bypass the system entirely with block-off plates since it only operates during cold start for emissions. Bypass plates available from Trail Gear or fabricated from aluminum.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 17600-0F010 secondary air injection pump assembly
replace a debris-damaged secondary-air pump after bulletin diagnosis Fitment/availability: Exact pump listed by T-SB-0230-12 Rev1 for an eligible 2005-2007 Sequoia 2UZ-FE; replace only when bulletin inspection finds debris in the pump Fi…
- Toyota 25710-50022 air switching valve assembly
replace the corresponding failed or debris-damaged air switching valve Fitment/availability: Exact air switching valve assembly listed by T-SB-0230-12 Rev1; use only on the diagnosed valve branch and confirm VIN before ordering Fitment/a…
- Toyota 25720-50011 electric air control valve No. 1
1 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 1 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.
- Toyota 25720-50020 electric air control valve No. 2
2 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 2 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.
- Toyota 89580-34012 air injection control driver
replace the air-injection control driver on the bulletin's residual-code branch Fitment/availability: Exact driver identified by T-SB-0230-12 Rev1; use only if P0418 or P2445 remains after the applicable mechanical repair and confirmatio…
- Toyota 17171-50030 intake manifold-to-head gasket No. 1
reseal both intake-manifold-to-head joints during the applicable repair Fitment/availability: Exact gasket listed by T-SB-0230-12 Rev1; bulletin quantity is two when the applicable air-injection repair requires intake-manifold removal Fi…
- Toyota 17377-50010 air tube gasket No. 4
replace disturbed air-tube seals during the bulletin repair Fitment/availability: Exact air-tube gasket listed by T-SB-0230-12 Rev1; bulletin quantity is four for the applicable repair Fitment/availability: Ships in 1-3 business days wit…
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Sources for this issue (2)
Lexus GX · 2003–2009
The secondary air injection (SAI) system pump and switching valves fail due to moisture intrusion and corrosion. The SAI pump introduces fresh air into the exhaust during cold starts to reduce emissions, but the pump motor corrodes internally and the switching valves stick. This triggers a check engine light with SAI-related codes.
Common Symptoms
- Check engine light with P2440/P2441/P2442 codes
- Rough idle on cold start
- Failed emissions inspection
- Whirring noise from passenger side of engine on cold start
How to Fix
Replace the secondary air injection pump and switching valves. Clean or replace the air injection check valves. Clear codes and verify operation. Some owners in non-emissions-testing states choose to bypass the system entirely with a tune.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- 17600-0F010 genuine Lexus secondary-air injection pumpOEM17600-0F010
Replace a commanded-test-confirmed failed secondary-air pump Fitment/availability: Live page explicitly fits 2004-2009 GX470 2UZ-FE/UZJ120. It does not verify the issue's 2003 year.
- 25710-50022 genuine Lexus secondary-air switching/diverter valveOEM25710-50022
Replace the diagnosed failed main air-switching/diverter valve Fitment/availability: Live page explicitly fits 2004-2009 GX470 2UZ-FE and supersedes 25710-50020/21.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipReplace both the pump AND the switching valves at the same time — if one has failed, the other is likely close behind. The valves are $150 each but save a second repair.
Toyota Sequoia · 2008–2019
2nd-gen Sequoias with the 5.7L 3UR-FE also suffer from secondary air injection pump failures, similar to the 1st gen but with updated part numbers. The pump seizes from internal moisture corrosion, triggering P2440-P2445 codes and check engine light.
Common Symptoms
- Check engine light with P2440-P2445 codes
- Loud buzzing or grinding on cold start
- Air pump not engaging on startup
- Failed emissions test
How to Fix
Replace secondary air injection pump (Toyota 17610-0S010 or Dorman 306-058). Replace air switching valves if corroded. Aftermarket pumps are available at lower cost. Some owners install check valves in the air line to prevent moisture backflow into the pump.
Sources for this issue (2)
Toyota Land Cruiser · 2008–2021
Subaru WRX STI · 2008–2014
Find P2442 by make
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P2442 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2442 mean?
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.
What are the most common causes of P2442?
The most common causes of P2442 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P2442?
Repair costs for P2442 range from $100 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P2442?
Au7o has documented P2442 across 7 vehicle models from 3 manufacturers: Lexus, Subaru, Toyota.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.