P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
12-10-2022, 01:42 PM
#1
P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
2003 Boxster S
Anyone dealt with this?
P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
P0492 Secondary Air Injection System, Bank 2 - Insufficient Flow
Tech notes:
Performed SAI Self Test: Failed.
Monitored input and output of secondary air pump. Was able to confirm activation of air pump and adequate flow. Will require removal of intake distributor to test remaining secondary air system components.
Anyone dealt with this?
P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
P0492 Secondary Air Injection System, Bank 2 - Insufficient Flow
Tech notes:
Performed SAI Self Test: Failed.
Monitored input and output of secondary air pump. Was able to confirm activation of air pump and adequate flow. Will require removal of intake distributor to test remaining secondary air system components.
12-12-2022, 05:47 PM
#2
Track Day
Join Date: May 2020
Location: Port Ludlow, WA
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It is possible to check several things before dismantling anything;
1, test the check valve connecting the vac system to the intake plenum
2. check the vacuum reservoir to see if it holds vacuum with the engine not running.
3. with the engine running at startup and the injection pump running, remove the vac hose from the switch controlling the injection pump control valve. You should hear a distinct change in the sound of the pump indicating that the vac switch and the check valve were/are operating correctly.
1, test the check valve connecting the vac system to the intake plenum
2. check the vacuum reservoir to see if it holds vacuum with the engine not running.
3. with the engine running at startup and the injection pump running, remove the vac hose from the switch controlling the injection pump control valve. You should hear a distinct change in the sound of the pump indicating that the vac switch and the check valve were/are operating correctly.