Purpose of secondary air system
Secondary Air System - SAS is used for injection of fresh air just behind exhaust valve in engine during short period when is engine cold and rich fuel is not completely combusted. This hot rich mixture is able to do secondary burn in exhaust thanks to fresh air injection and thus catalytic converter is heated faster and hydrocarbon emissions are lower. Well that is theory. 
Is this system mandatory?
In short No. Engine will work perfectly fine even without this system and its components, problem is that ECU is reporting error when system is not working or is removed and to annoy owner even more it turn off traction control and cruise control to force you for workshop visit. Bypass is emulating SAS values to ECU so it thinks that system is present and fully working. On emission test is everything fine because test is made on warm engine so no problem here.
How I know that I have SAS failure?
When ECU detect SAS problem it will light up MIL light and cruise will be flashing, Any OBD II reader can read cault code for this system and will report you error code. If you observe fault code related to SAS system (listed below) then you can solve it by bypass.
- P0410
- P0413
- P0414
- P0418
- P1410
- P1418
- P2432
- P2433
- P2440
- P2441
- P2444
Problem solution
Bypass is based on original schematic from some russian fans, anyway original schematic used relays which was not perfect for low signal currents and emulated values was not working in all conditions. Circuit was improved and made solid state in waterproof design with original automotive connectors for easy and long lasting installation. For car years 2010+ is new bypass with pressure reading necessary, otherwise ECU will use wrong data for fuel mixture. For orders and pricing contact me on email HERE.
Module is compatible with all Subaru cars which have pressure sensor in ECU(Legacy/Outback 2005-2009, wrx up to 2007). For models 2010+, which are using pressure sensor in combination valve is bypass module 2010+.
Návod na instalaci modulu pro vyřazení systému sekundárního vzduchu do roku 2010
Návod na instalaci modulu pro vyřazení systému sekundárního vzduchu od roku 2010 včetně
If is required to remove SAS valves because of design or weight, or valves are leaking exhaust fumes, then blanking flanges are available including exhaust seal.
