Secondary Air Injection

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Secondary air injection is an emission control system that uses pumped air to improve the gas emitted by the exhaust. 
The secondary injection pump pumps in fresh air from the surrounding into the vacuum valve, which in turn opens into the exhaust as a result of the impulse coming from the ECM. This freshly pumped air goes into the exhaust manifold at cold start to react with the excess CO and HO that were produced due to the excess fuel that was injected into intake manifold during the cold start before it goes into the atmosphere. 

P2442 - secondary air Injection system switching valve stuck open bank 1.
P2440- secondary air injection system switching valve stuck open bank 2.
Symptoms 
  • Check engine light on. 
  • Engine hesitates while accelerating. 

Causes
  • Faulty vacuum switching valve.
  • Vacuum switching valve harness open or shorted. 
  • Vacuum switching valve circuit poor connection.
  • Faulty pressure sensor
  • Faulty air switching valve. 

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