Bob 
2002 Nissan Altima Sedan 2.5 S 4dr Sedan (2.5L 4cyl 5M)
Engine Failed at 95k miles
 Pre-catalyst came apart at 95k miles after a recall supposedly fixed the problem.  The pre-cat came apart and is close enough to the cylinders that it ruined the engine (the 2005+ models have the pre-cat moved farther away to permanently solve this problem).  Nissan has rejected all warranty claims on any cars outside of 60k miles.  $4600 to fix it.  The only permanent fix is an aftermarket header that puts car out of emissions compliance.