I have a AP1 s2k showing p0411 2ndary air injection incorrect flow.Ive searched around and havent found a solid answer to this.Do i need to replace the air injector or could it be a vacuum issue?The only mods are a k&n air intake and the check engine light didnt show until the idle was fixed because the idle was previously at 1800 rpm

 

It could be the air pump or hose like you said, or even the solenoid. If someone has messed with the vacuum lines recently then the two hoses may be switched around, if not then something needs to replaced

 

Could be the connection of the rubber hoses that come with the FIPK that take the place of the hardlines... Check by the throttle body to make sure the rubber hoses are connected correctly. Just an idea... Hope you get er fixed up

 

i have the same problem. i replaced the air pump, checked all the lines all summer. still havent gotten it fixed. when i get my car out next month ill keep trying.

 

It's a super common problem with MY00-05 S2000's. There is even a service bulletin at Honda on this. It is caused my vacuum leaks or air pump/solenoid malfunction. Happened to my car, replaced the air pump with a used one at the scrapper. Issue went away. It's not something to be too worried about. It's for emissions more than anything. It only comes on for about a minute during cold starts to regulate idle.

 

P0410 is the code for the actual pump. A P0411 could mean that one of the vacuum lines was missed or lose after switching over to the K&N intake. You should check over all the hoses and make sure everything is on and tight.