Can you keep driving?
Can you keep driving?
Stop driving if any of these apply
- !The engine starts running much worse, stalls, or the warning light flashes.
- !The vehicle begins to overheat, knock, or lose power sharply while the code is active.
What to check first
Step-by-step checks
- 1
Free - no tools
Let the exhaust cool before checking the valve and wiring
- 2
Free - no tools
Inspect the valve connector and harness for heat damage, corrosion, or a pinched wire
- 3
Basic tool needed
Check whether the code appeared after cold weather, wet conditions, or recent exhaust work
- 4
Basic tool needed
If the valve is vacuum-operated, inspect the solenoid and vacuum lines too
- 5
Basic tool needed
If scan data is available, compare commanded operation with actual response
If the code returns
- -If the valve does not respond to command, the valve or control side moves higher on the list.
- -If the harness movement changes the fault, wiring repair comes before a new valve.
- -If the code returns after replacement, recheck the connector fit and control command path.
Background
What this code means
P0414 is a generic OBD-II code for a secondary air injection switch valve A circuit malfunction.
This code usually points to the valve side of the system, where the ECU expects a specific change and does not see it.
Diagnosis
Common causes
Failed switch valve
The valve may no longer open or close reliably.
Connector or wiring issue
A poor connection can interrupt the valve circuit.
Vacuum supply problem
On vacuum systems, the valve may not be getting the pressure it needs.
Moisture or corrosion
Water intrusion can damage the valve or its circuit.
Avoid these mistakes
What not to do
- xDo not replace the sensor or valve first if there is obvious wiring, connector, or vacuum damage.
- xDo not ignore drivability changes just because the code sounds like an emissions fault.
Parts
Parts that may need replacing
See also
Related OBD codes
P0410
P0410 usually means the secondary air injection system is not working properly.
P0411
P0411 usually means the secondary air injection flow is incorrect.
P0412
P0412 usually means the secondary air injection control circuit has a malfunction.
P0413
P0413 usually means the secondary air injection valve circuit is malfunctioning.
Source notes
Generic OBD-II (SAE J1979 / ISO 15031-5). P0414 was expanded around common secondary-air switch-valve faults, including valve failure, wiring damage, and vacuum supply problems.
This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.
This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.
Last reviewed: 2026-04-10
Reference: Open reference