P1423 OBD Code Definition:
P1423 EGI Functionality Test Failed
P1423 OBD Code Description:

Possible Symptoms

• Malfunction Indicator Light (MIL) active

Possible Causes

• Fuse for Secondary Air Injection Pump blown
• Vacuum Hose(s) leaky or collapsed
• Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve leaking
• Secondary Air Injection Solenoid(s) faulty
• Combi Valve(s) faulty

Possible Solutions

• Check Fuse for Secondary Air Injection Pump
• Check Vacuum Hose(s)
• Check Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve
• Check Secondary Air Injection Solenoid(s)
• Check Combi Valve(s)

Tech Notes

On vehicles with rivets holding the plastic body halves of the Secondary Air Pump together check to see if the rivets are falling out. If they have fallen out or are loose you may be able to bolt the pump back together if the motor has not failed.