What does it mean?
P1424 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Secondary Air Injector System (Bank 1) Leak Detected . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- MIL on and the secondary air readiness monitor stays incomplete
- Hissing or blowing noise from the engine bay while the pump runs on cold start
- Higher hydrocarbon emissions and a raw exhaust smell in the first minute
- Slightly rough cold idle
- Pump audible and working, but the exhaust side shows little or no change in oxygen sensor data
Likely causes
- Split, softened or heat damaged air delivery hose on the Bank 1 side
- Loose or corroded hose clamp at the pump, valve or manifold connection
- Leaking gasket between the air injection pipe and the cylinder head or manifold
- Cracked or corroded metal air injection tube, common where it runs close to the exhaust
- Check valve not sealing, letting pressure escape back through the line
- Air valve not closing fully, so system pressure cannot build during the test
- Cracked pump housing or a leaking pump outlet fitting
How to fix it
- Start the engine cold and listen carefully for air leaks while the pump is running
- Inspect the Bank 1 hoses, clamps and metal tube for splits, corrosion and heat damage
- Check the air injection pipe to head or manifold joint for a blown gasket, looking for soot tracks
- Apply low pressure air to the delivery line with the pump disabled and listen or use soapy water to find the leak
- Remove and test the check valve for correct one way sealing
- Verify the air valve closes fully and seals when it is not commanded
- Replace the leaking hose, gasket, tube or valve, then run a cold start monitor to confirm the code is gone