What does a secondary air injection pump do?
An air pump, also commonly referred to as a smog pump, is an emissions component that is part of the secondary air injection system. It is responsible for pumping clean air into the vehicle’s exhaust stream to promote a cleaner and more complete burn before the fumes exit the tailpipe.
What is the secondary air pump on a BMW?
What is the purpose of the secondary air pump? The primary purpose of the secondary air pump (SAP) is to reduce harmful emissions. Hydrocarbon (HC) and Carbon monoxide (CO) gasses are the two main gasses which contribute to smog.
What is P0491?
Diagnostic trouble code (DTC) P0491 stands for “Secondary Air Injection Insufficient Flow Bank 1.” It is logged once the vehicle’s powertrain control module (PCM) perceives that there is a possible issue within the SAI system. This code is logged once the PCM determines that the secondary air flow in bank 1 is too low.
How do you test a secondary air injection?
The secondary air valve can be quickly inspected in an easy way:
- Loosen the connecting hose on the secondary air non-return valve leading to the secondary air pump.
- If there are deposits on this side of the valve (finger test, see Fig.
- Inspect the secondary air pump and replace it if necessary.
How do I fix code P2258?
What Repairs can Fix the P2258 Code?
- Repair or replace any damaged one-way check valves.
- Repair or replace any damaged or defective switches.
- Repair or replace any damaged or defective hoses or fittings.
- Repair or replace any damaged or defective wires and connectors.
Can you drive with a bad air pump?
Repairing a bad air pump While failing a smog test is a serious enough problem, the real danger from a bad air pump is the possibility that reduced engine performance and driveability could cause be hazardous to your driving safety.
How do I fix error code P2431?
What repairs can fix the P2431 code?
- Replacing the secondary air pump.
- Repairing or replacing a wiring harness.
- Resolving poor electrical connections.