Which DISA is bad on N54B30 engine?

[jonno426]

I have a CEL with the notorious lean bank engine codes and the common rough idle when it's cold. I have narrowed it down to the DISA (I think). The question I have is when I look up a DISA for the E70 3.0 SI it comes up with a lower and upper. How ridiculous is that?!

To add to my recent X5 woes I really don't want to buy both at the moment, as I've recently had catastrophic cooling system failures (resulting in the replacement of the radiator, hoses, thermostat, water pump at the dealer) and also getting a simple valve cover gasket leak fix entailed them having to replace the wiring harness and starter as well.

I'm not too sure trading in my car payment for something paid off like this was the truly smart decision anymore ...

btw it's a 2008 x5 3.0si with a hair over 68k miles.

Thanks for the help in advance!