No lender will be able to?count?boarder income. They could use it as a compensating factor, but HARP loans are not manually underwritten (they are underwritten by Fannie/Freddie's automated systems) so that doesn't really make a difference.
If Chase can't do it for you and DTI is the issue something will have to change in your debt ratio. Moving out is not a good idea, as the rental income would not be able to be used for qualifying right away anyways. And if if it could you could only use a maximum of 75% of the actual income against the payment.
But maybe there is an expense you can get rid of? How many cars do you have? Can you pay off a credit card? Something like that?