Ya'll check this out. My gf drives a '05 Nissan Altima that already needs an engine because of a very poor design in the layout of the exhaust manifold and pre-cat. You can read all about it here:
Nissan engine problems
I had a Nissan Hardbody that went 300k miles before the timing chain broke and put the truck out of it's misery. It is like I told the service manager who I called and inquired about a recall "I used to hold Nissan in pretty high regard". When you call them and mention the pre-cat failure and the symptoms they refer you to the parts department to get a price on an engine. I was surprised but you can purchase a factory long block for these cars for $2400 and get it in two days. I can't even cover the parts for a W123 rebuild for that.