01 Does replacing engine head gaskets extend the life of the e… • 02 Why Aren’t the Rear Tires on Cars Made to Turn Like the Fro… • 03 How to Tell If Your Engine Valves Need Adjustment • 04 Troubleshooting a Hard Brake Pedal: Causes and Solutions • 05 Understanding Why Brake Calipers Are Sticking When Hot • 06 Why is your car shaking when you brake at high speeds? • 07 Converting a Petrol Car to LPG: Benefits, Process, and Cons… • 08 Why Does My Car's RPM Go Up and Down at Idle? Causes and So… • 09 From Slight Pause to Complete Failure: Understanding Transm… • 10 LED vs Halogen Headlights: Which One is Better for Your Car? •

DTC codes / GM codes / P1416

P1416 · GMAIR System Bank 1

P1416 on GM vehicles indicates that the powertrain control module has detected a fault in the secondary air injection (AIR) system for bank 1 of the engine. The computer monitors the AIR system's ability to deliver fresh air into the exhaust stream during cold starts, and this code sets when the expected change in oxygen sensor voltage or air pump current does not occur within the test window.

SystemPowertrain
Code typeGM specific
SeverityLow
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms
  • Slight rough idle or hesitation during the first few minutes after a cold start
  • A brief, faint hissing or whining noise from the engine bay during cold-start air pump operation
  • Failed emissions test due to incomplete readiness monitors or increased tailpipe emissions
  • In rare cases, a noticeable delay in catalytic converter light-off causing a rotten egg smell

Common causes, most likely first

  1. Faulty secondary air injection pump that does not spin or produces insufficient pressure
  2. Disconnected, cracked, or melted air injection hoses or tubing between the pump and the exhaust manifold
  3. Failed air injection check valve that is stuck open or closed, allowing exhaust gases to back up into the system
  4. Blown fuse or corroded relay in the air pump electrical circuit
  5. Damaged or disconnected vacuum line to the air injection control valve (on systems that use vacuum actuation)
  6. Corroded or damaged wiring harness at the air pump connector or ground point
  7. Failed air injection solenoid or control module that prevents the system from activating

How to diagnose and fix it

  1. Inspect all secondary air injection hoses and tubing for cracks, disconnections, or melting, and repair or replace as needed
  2. Check the air pump fuse and relay, and test the relay operation with a multimeter or by swapping with a known-good relay
  3. Command the air pump on with a scan tool and listen for operation; if silent, check for battery voltage and ground at the pump connector
  4. Test the air injection check valve for proper one-way flow and replace it if it leaks or is stuck
  5. Verify vacuum supply to the air injection control valve (if equipped) and check the valve diaphragm for tears
  6. Perform a resistance test on the air pump motor and compare to specification; replace the pump if open or shorted
  7. Clear the code and complete a cold-start drive cycle to verify the repair and confirm the monitor runs without resetting

Common Misdiagnoses and Hidden Causes for P1416

  • A stuck-open air injection check valve often mimics a failed air pump because exhaust backpressure can damage the pump, so always replace the check valve when replacing a pump to prevent repeat failure.
  • Many technicians replace the air pump without checking the fuse and relay, which are common failure points on older GM trucks and SUVs, leading to unnecessary parts replacement.
  • The P1416 code can be set by a simple disconnected vacuum line to the air injection control valve, a cheap and easy fix that is frequently overlooked during diagnosis.
  • On some GM engines, a faulty oxygen sensor or exhaust leak upstream of the air injection point can cause false P1416 codes, so verify oxygen sensor operation before condemning the AIR system.
  • The AIR system only runs for a short period after a cold start, so intermittent faults may not appear during a warm-engine inspection; always perform diagnostics with the engine cold.

Can I keep driving with P1416?

You can continue driving with P1416 because the secondary air injection system only operates briefly during cold starts and does not affect engine performance or safety. However, avoid long-term neglect since the fault increases cold-start emissions and may eventually damage the catalytic converter if a check valve fails.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage