I have a 98 nissan maxima & the other day I noticed white smoke from the tailpipe & a few other things I have noticed that has me seriously stumped. 1st- White smoke from tailpipe.
2nd- Oil only one spark plug.
3rd- Idles up & down
4th- Hard shift into 2nd gear.
5th- After trying to drive it, the idle goes up & down & then eventually shuts itself off.

 

wrong section, you want the 4th gen section. but

1- white smoke if its cold outside is just water vapour, if its thick and sweet smelling youre burning coolant probably

2- could be a valve cover gasket leaking

3- could be many things, check for vacuum leaks to start

4- check the fluid level and condition if its a automatic, if its a 5spd check the fluid level. if its a 5spd its probably synchros or a linkage issue

5- again check for vacuum leaks, or scan it. might come up with a MAF code