P2442 Code: Secondary Air Injection Switching Valve Stuck Open Bank 2
The bank 2 secondary air valve on a V engine doesn't seal, so exhaust pulses reach the air pump side.
At a glance
Severity: Moderate
- Meaning
- Secondary Air Injection Switching Valve Stuck Open Bank 2
- System
- Emission Controls · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $80–$3,800
- DIY difficulty
- Hard
P2442 only exists on V-type engines with secondary air injection, because it concerns the switching valve feeding bank 2 – the cylinder bank that does not contain cylinder 1. The ECM expects that valve to seal tightly once the post-cold-start air cycle ends; when the AIR pressure signal keeps showing exhaust pulsation afterward, or the air system behaves as if bank 2 is still connected, it stores this code. By far the best-known case is Toyota's 4.7-liter and 5.7-liter V8 in the Tundra, Sequoia and Land Cruiser and the related Lexus models, where the electric air switching valves corrode internally from condensation. It commonly appears together with P2440 for bank 1 and with air pump codes, and on these trucks the ECM often turns on the VSC/TRAC lights and limits power as well.
Can I keep driving? You can usually get home or to a shop, but reduced power in limp mode makes merging and towing risky – don't tow with the code active. Get it repaired rather than repeatedly clearing it, because the leaking valve lets hot, wet exhaust attack the pump and hoses.
How to read P2442
- P Powertrain
- 2 Generic (SAE)
- 4 Auxiliary emission controls
- 42 Specific fault
Symptoms
- Check engine light with VSC, TRAC or slip indicator lights on many Toyota trucks
- Sluggish acceleration or reduced power (limp mode) on some vehicles
- Rattle, groan or no sound from the air pump at cold start
- Code appearing after a car wash, heavy rain or a water crossing
- P2440 and pump codes stored at the same time
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Bank 2 air switching valve corroded inside and not sealing
- Water drawn into the air system through the pump inlet, damaging valves on both banks
- Valve control stuck on – shorted driver, relay or air injection driver module
- Heat-damaged connector or wiring to the bank 2 valve
- AIR pressure sensor or its signal wire reading pulses that aren't there
- ECM fault or outdated calibration
Diagnosis step by step
Decide whether it's one bank or both
Check whether P2440, pump or relay codes are stored too. P2442 on its own points to the bank 2 valve; together with P2440 and pump codes it usually means water has gone through the whole system and both valves and the pump need attention.
Tools: OBD-II scanner
Compare AIR pressure readings
With the key on and engine off, the AIR pressure reading should match barometric pressure. With the engine idling warm and the system off, a steady reading is normal; a fluctuating reading that follows engine pulses indicates a valve that isn't sealing.
Tools: OBD-II scanner
Check that the valve is really switched off
Back-probe the bank 2 valve connector at warm idle after the cold-start cycle. There should be no command voltage; if the valve is still being powered, look at the relay, the air injection driver and the ECM output before buying a valve.
Tools: Multimeter
Inspect the bank 2 connector and harness
The valve sits at the back of the engine close to hot exhaust parts. Look for brittle or melted connector housings and green corrosion on the pins, which can cause erratic readings.
Tools: Flashlight
Assess the air pump
Command the pump on and listen, then check its outlet for water or rust. A pump that grinds, draws excessive current or blows its fuse should be replaced along with the valve.
Tools: OBD-II scanner, Multimeter
Run the system check after repair
Some dealer-level scan tools offer an air injection system check that runs the test without waiting for a cold start. Otherwise clear the codes and let the engine cool overnight before confirming.
Tools: OBD-II scanner
Where the parts are
- 1Upstream O2 sensor
- 2Catalytic converter
- 3Downstream O2 sensor
- 4Diesel particulate filter
- 5Turbocharger
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Repair heat-damaged valve connector or wiring | No | $80–$300 |
| Replace AIR relay or air injection driver | No | $120–$600 |
| Replace bank 2 air switching valve | No | $400–$1,200 |
| Replace both switching valves | No | $800–$2,200 |
| Replace both valves and air pump | No | $1,800–$3,800 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Toyota
On the 4.7L and 5.7L V8 Tundra, Sequoia and Land Cruiser, P2440 and P2442 often appear as a pair with air pump codes. Many shops replace both valves and the pump at once, because a single-valve repair is often followed by a failure on the other bank.
Field data
| Toyota | 105 | ||
|---|---|---|---|
| Subaru | 2 | Impreza, Wrx |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P2442 keeps the check engine light on, which fails an OBD-based smog check. After the repair, the secondary air monitor has to complete during a cold start (or a scan tool system check) before the vehicle will pass.
Frequently asked questions
Which side of the engine is bank 2?
Bank 2 is the cylinder bank that does not contain cylinder 1. Which physical side that is varies by engine, so check the service information for your engine before removing a valve.
Should I replace both valves if only P2442 is set?
It depends on condition and budget. If the bank 1 valve and pump are dry and working, one valve may be enough; on high-mileage Toyota V8 trucks the other valve often fails soon after, so replacing both saves a second round of labor.
Why did the code show up after I washed the engine or drove through water?
The air pump draws in outside air, and water getting into the pump inlet or hoses can reach the valves and corrode them. Once a valve stops sealing, it only gets worse.
Is it safe to keep driving in limp mode?
For short trips at normal speeds, generally yes – the engine isn't being damaged by the code itself. Avoid towing and highway merging with reduced power, and don't just keep clearing the code.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy