If your 2005–2015 Tacoma with the 4.0L V6 throws P2440, P2441, or P2442 and the check-engine light is on, the culprit is almost always the secondary air injection (AIR) system — typically a stuck or corroded air switching valve, sometimes the pump itself. This is one of the most common and most expensive check-engine causes on the 1GR-FE. A dealer repair with both OE valves and the pump can run $2,000–2,500; a single failed valve replaced yourself runs about $300. The system only operates for the first couple minutes of a cold start, so the truck drives fine — it is an emissions code, not a drivability emergency.
The secondary air injection system exists to clean up the exhaust during cold start. For roughly the first 60–120 seconds after a cold start, an electric pump forces fresh air into the exhaust stream through valves on each cylinder bank, helping the catalytic converters light off faster. It is a Toyota-specific design on the 4.0L, and over time corrosion seizes the valves or the pump fails — both very common, especially on 2005–2009 trucks and on any truck that sees moisture, salt, or sits a lot.
The codes, decoded. P2440 and P2441 point to the air switching valve (bank 1, stuck open or stuck closed); P2442/P2443 cover bank 2. P0418 and related codes can point at the pump relay or pump circuit. The ECU runs a self-check on cold start, and when the valve doesn't move or airflow isn't seen, it sets the code and the light. Pull freeze-frame data — it confirms the fault happened at cold start, which fits the AIR system.
Why the dealer bill is brutal. The OE fix is to replace the failed valve(s) and, if the pump is bad, the pump — all genuine Toyota parts, plus labor to reach them. Two valves and a pump in genuine parts alone approach $1,200, and the labor stacks on top. This is sticker shock for what is, mechanically, an emissions accessory.
The realistic DIY paths. Most failures are a single seized valve, not the pump. Diagnosing which valve failed and replacing only that one drops the cost to around $300 in parts. Some owners clean a lightly corroded valve and reset the code as a temporary measure, though a cleaned valve often re-fails. Aftermarket bypass/block-off kits exist that simulate the system to the ECU — but installing one to defeat a functioning emissions system is illegal under federal law and will fail emissions testing where required. Whether a bypass is street-legal depends entirely on your state and inspection rules; in Arizona and many areas, emissions tampering is a violation. Repair the system if your area tests emissions.
Does it affect how the truck runs? No, and that is the saving grace. The AIR system only operates briefly at cold start. With it disabled or failed, the truck idles, drives, and makes power normally — you are left with a check-engine light and a failed emissions test until it is repaired. There is no need to panic or stop driving.
| Part | Vendor | Est. price |
|---|---|---|
| OE secondary air injection valve (driver/passenger, each) | Toyota | ~$280 |
| Secondary air injection pump (OE) | Toyota | ~$650 |
| Aftermarket bypass/block-off kit (where emissions-legal) | various | ~$120 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.
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