P0416 — Secondary Air Injection System Switching Valve B Circuit Malfunction
Can drive — fix at your convenience.
What P0416 means
This code means the engine computer detected an electrical problem in the control circuit for the secondary air injection switching valve 'B'. This valve directs air into the exhaust to help burn off pollutants when the engine is cold. The fix usually involves repairing wiring or connectors, or replacing the switching valve itself, and it's typically not a major engine repair.
Common symptoms
- Check engine light is on
- No noticeable change in how the car drives
- Failed emissions or smog test
- Possible rough running right after a cold start
- Slightly higher tailpipe emissions
Common causes
- Faulty secondary air injection switching valve
- Damaged or corroded wiring in the valve circuit
- Loose or corroded electrical connector at the valve
- Failed relay supplying the valve
- Problem with the engine control module or its driver
Typical repair cost
$120 – $450
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0416 code?
Yes, in almost all cases you can keep driving normally. This system only affects cold-start emissions, not how the engine performs or its safety. Just plan to get it repaired before any emissions test.
How much does it cost to fix a P0416 code?
Most repairs land between $120 and $450. A simple wiring or connector fix is on the lower end, while replacing the switching valve costs more depending on your vehicle.
Is a P0416 code serious?
It's a low-severity code. It won't leave you stranded or damage the engine, but it will keep the check engine light on and can cause an emissions test failure.
What is the secondary air injection switching valve?
It's a valve that routes fresh air into the exhaust system during cold starts to help burn unburned fuel and lower emissions. Valve 'B' is simply the designation for one of these control valves on your engine.