I have just purchased a 2001 Honda S2000 with an Injen cold air intake. It threw the code P0411, so maybe the two are related. As far as I know that is the only modification done to the car. Any advice on how to fix it? I'll need detailed help as I am not very experienced. Thank you for any input.

 

I've seen this code before. When I took the intake box out to clean it. I forgot to hook up a vacuum hose. Listen for sounds of a vacuum leak. I believe the code is coming up because one of the hose might be hooked up backwards or there might be a tear on the actual hose itself. I hope this helps

 

One of your vacuum lines is backwards. Pay special attention to the vacuum lines running from near the fuel rail to the purge valve.

 

Is there any way to tell which hose it would be?

 

Here's a picture if it's of any use

 

Perhaps your engine codes are related to this?

https://www.s2ki.com/s2000/topic/115...-chewed-threw/

 

Need a better view of where the vacuum lines end up at the purge valve. Here is a decent picture.

 

I'm not sure if they could be related. I have no idea what those wires do.

Here's a better picture I think

 

Those lines are directly related to your code because they hook up to the secondary air injection system!

It looks like the top vacuum line coming from the fuel rail is connected correctly but the lower one might not be connected to the solenoid at the right point. I'm talking about the solenoid that is attached to the intake arm. Try swapping the vacuum lines on the solenoid. Not sure if you have to clear the codes or not.

 

here is a similar thread: https://www.s2ki.com/s2000/topic/1026850-p0411-code/

post #4 has a very clear diagram of the vac lines. make sure yours match!