Mastering P0491 A Comprehensive Guide to Troubleshooting

The diagram shows the check valve that is installed in the intake has a single vacuum line that runs to the vacuum canister, however the check valve in my car ... Possible Causes · Fuse or relay for Secondary Air Injection Pump faulty · Hose(s)/Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) ... The car will need to be in closed loop or hot for the 02 sensors to read the air input correctly. Code P0491 Secondary Air Injection System (Right Bank). Subscribe. Feb 3, 2006 | 10:03 PM. If you're seeing this code, it means the powertrain control module (PCM) has identified that the SAI system is dealing with insufficient flow. It was running like a dream, but recently threw a code. P0491. I checked the code and it's the secondary air Injection. I have had the hardest ... The error code P0491 can be defined as Secondary Air Injection System Insufficient Flow Bank 1. This trouble code indicates that there is an issue on the side ... Performed SAI Self Test: Failed. Monitored input and output of secondary air pump. Was able to confirm activation of air pump and adequate flow. Secondary AIR Diag VW Jetta P0491 part #1 part #2 https://youtu.be/GtQySXD7yPA?si=vWP3gwqqnzGvDV1i more diag tips for this problem before ... The PCM will set the 0491/0492 codes based on what the O2 sensors see. So if there is a link then perhaps the faulty PCV valve is changing the exhaust mixture.