Chris Moore 
2003 Nissan Altima Sedan 2.5 SL 4dr Sedan (2.5L 4cyl 4A)
buyer beware
 Bought the car with 28,000 miles on it and my wife put 40,000 miles on it in about 7 years. I kept the oil changed and tires on it with no real problems, except for the door handles breaking, until recently. First the engine light came on sporadically and I could feel engine hesitate. Got the code checked out and it's was somewhat generic (p0300) with up to five different system that could be the problem. I changed the plugs and ignition coils and the motor ran better but there was another problem. Took it to a garage and have the exhaust manifold and catalytic converter replaced. Cars running just fine again. One week later the oil light comes on and I add 3 quarts and I'm going to run the car for around 1k miles before I take it to get an oil change. Within another week or two the car starts sounding like the exhaust manifold is bad again. Before I can get the car to the shop it dies on the side of the road. Look at the oil and it's black with less than 500 miles since I put the 3 quarts in. The engine is now dead and I've already put around $2k into the car in the last 2 months. This really sucks for a car that I thought would last well over a 100K miles. I'll never buy another Nissan again. If you want to see all the problems with this motor look up misfires, exhaust manifold, and precat.