P0491/2 + Misfires Problem

[Lacostas]

Originally Posted by JFP in PA

P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
P0492 Secondary Air Injection System, Bank 2 - Insufficient Flow

Possible cause of fault
- Electrical fault in power supply or line between relay and secondary air injection pump
- Secondary air injection pump relay mechanically faulty
- Mechanical fault in electrical secondary air valve
- Pneumatic secondary air valve faulty/sluggish
- Electrical fault in secondary air injection pump
- Mechanical fault in secondary air injection pump or secondary air injection pump blocked
- Vacuum system leaking
- Air hose to secondary air injection pump slipped off or constricted

Thanks, do you have any idea which one i can start checking first ? Maybe it would be better/easier/faster (but more expensive) to get a new SAI Pump and check if that is the case?
Or even get the old pump out and get it tested to a local indy around the island ?