I've had the 1320 header (v1) for a little over 2 years now. It whistled a bit, but nowhere near as bad as some.
A couple of weekends ago it started going crazy with a really loud whistle. Then last night it threw a P0171 CEL (system too lean).
Had a look at it and:
Flexi is utterly destroyed already. Think I'm done with this, I don't want to throw good money after bad trying to get this POS into a working state.