I'm not sure where the FPR(fuel pressure regulator) is located on the v6, but on the i4 it was pretty easy to change...took about 5minutes and cost about 30$ at the local dealer here.
The FPR on the v6 is located just behind the throttle body. It's also pretty cheap to replace. Not sure if I should get just the FPR and hope that fixes the problem or not though. Don't really want to spend money if there's a chance it won't fix the problem.