I have a similar problem with my car turning over but not starting. I already replaced the Camshaft (front) but I haven't done the back one. When I replaced the front one, it seemed to get a little better but it's still not quite right. Do you think if I replaced the back one that it would fix my problem? I am working on a 2005 Nissan Murano.

First, check for codes. Are you saying you have already replaced the Camshaft Position Sensor? Camshaft Position Sensors and Crankshaft Position Sensors have been problems on Nissans. If you have replaced one, I would do the other.