Hey guys, i've been getting a SES light for a little while now, i have already replaced the check valve, inspected the hose, and made sure the clamps were tight. I also cleared the code every time i've changed something aswell. The code keeps coming back. Is it possible my Passenger side O2 sensor is bad? What else would cause this?

Thanks Alot in advance!!

 

Are you sure the air pump functions? If not try jumping the red wire going to the pump to +
+12V and see if the pump kicks on.

 

When you jump the pump wiring, and its operating, verify there is air flowing out of both check valves.