Can anyone help with this code? P0411 Secondary air, injection system, incorrect flow. I am looking to fix the issue but do not know what to fix. I recently replaced the O2 sensor - bank 1 sensor 2 for other codes but I don't know how to deal with this one.

 

Hello Leone

Typically, the fault is either with the AIR pump, or the Checkvalve between the pump and the exhaust. I know it seems extreme, but often times when it is the pump that is faulty, its because of a bad checkvalve! The checkvalve (which is supposed to keep exhaust out of the air pump lines) leaks and allows exhaust to back up into the pump where it condensates and the moisture buildup ruins the pump. anytime I replace the pump I replace the checkvalve. If you hear your pump come on at startup, try replacing the valve first and if the code comes back, do the pump.

 

Thanks. I appreciate the advise.