Your powerloss sounds like a known issue with your engine. There was a recall on these in 2005. Mine's going in to a Nissan dealer in a few days for a few recall fixes; headlights and ECU (probably will fix my smoke problem).
Specifically: "Concern related to the Engine Management System has been identified. This can lead to a lack of power, poor acceleration response, black smoke from the exhaust and/or whistling noise".
Recall fixes are free at any Nissan dealer.
Hope this helps.