At work and it is too noisy to get much out of the clip.
This may be of some value: My 2002 Boxster manifested low volume rumble sound shortly after cold start. This at around 172K miles.
Because the noise was not very loud it was impossible for me to know where exactly it was coming from and fearing the worse I suspected from inside the engine. Thus I went through the trouble of removing the serpentine belt and starting the engine to confirm the noise was not present at cold start with the belt removed.
Since the belt was off I checked all accessory drives for play and the water pump had some. Not much but it had some where as the other accessory drives had none. The belt had a sharp edge, too, which indicated it was not tracking properly. (The belt was very new and I had the old belt handy and it had dull edges so the sharp edge was a recent thing.) So I diagnosed "water pump" and had the car flat bedded to a dealer and the water pump/T-stat replaced. Noise gone. (And the replacement pump has 141K miles on it.)
You should be able to distinguish between a possible noisy water pump and some other source of the noise. You might have to remove the engine cover and expose the engine though.
Also, If you think the noise from the secondary air injection pump you can I believe pull a fuse or disconnect the pump from the electrical harness and start the engine. The CEL may come on if you run the engine long enough but you only run it long enough to confirm the noise is still present or not. If still present you don't have the secondary air injection pump noise to filter out.
You sure about P0401? Maybe you mean to type: P0410?
Anyhow, for P1411:
P1411 Secondary Air Injection System, Bank 2 – Below Limit
Possible cause:
- Secondary air injection pump is not triggered
- Secondary air injection pump does not function
- Air supply lines restricted
- Electric change-over valve does not function
- Air change-over valve does not function
- Vacuum system leaking
I'd be careful about configuring the car to operate sans the secondary air injection pump. While it is true CA has some rather stringent emissions requirements that would make removing this a real problem other states can require a functioning secondary air injection system and the readiness monitor that goes with this, too.
If the secondary air injection system has suffered from some mechanical failure there can still be a problem if the failure is a leak so unless you remove the entire system there can still be a problem arising from the leak. And in removing the system then you have to seal up the hose connections, etc. If not done right this can cause other problems that might be harder to diagnose without the benefit of the DME support for the secondary air injection system and the diagnostic codes it would provide.