I purchased the 2002 Nissan Altima 2.5S July 3, 2006. Two weeks having the car my check engine light came on. The code read multi cylinder misfire. I reported it to the Nissan dealer where I purchased the car from and I was told I had to pay for them to look at it, eventhough I just spent $12,500 with them. I took it to my mechanic and he changed the spark plugs out. In February 07 the light came back on and it was the same problem. I got the fuel system cleaned, plugs, and both O2 sensors changed. I then took it to another Nissan dealer to find out why was the code kept coming back. They told me to monitor the coolant because it could be cracked head gasket at 85000 miles. The coolant never went down and the car started to crank but would not start. I took it to the dealer and they could not duplicate the problem for an entire month. They replace coils, plugs, fuel pump, and cleaned for residual from the gas flooded engine. After thinking it over I decided to go ahead and get the head gaskets fixed after 6 weeks at the dealer. 2 weeks after I got that done my car has died on me. Nissan Consumer Affairs was notified twice, BBB was notified, and the dealer where I bought the car from knows about this car. No one wants to help me out on this. I've had the car for 1 year and it needs a new engine. The engine seemed to be defective by all of these problem. There should be a class action lawsuit to protect consumers like me.