So i bought an uplander 2008 3.9 last march but did not put it on the road til this june. The previous owner had just got it going after sitting for a yr or more then i let it sit a yr. When i bought it it ran an drove fine some dash lights on. When i put it on the road in june i was experiencing some check engine light issues. Like map sensor to high but it corrected itself? Also lean bank 1 off an on. I changed front plugs looked old #5 plug was ate away but still fired i guess. I had noticed what felt like a miss on highway speeds every couple hundred ft off an on. New front plugs did not fix it. A new thing happened this week after small 37m trip with highway and city driving when i got off xway and went to accellerate trans was bang shifting. 1 mile to home. Next day normal again. This has happened last 2 times i took same trip. When i checked fluid before getting it licensed i noticed metal dust in it. Just checked today and its clearer. But color is off. Maybe its more silver? Abs an traction light is on sometimes driving gets it to go off. 1 tire pressure is on and off another reads wrong now. Vehicle has rust holes in front of rear wheels pass side worse. Thats it for now......

How many miles on it?

Change all the plugs, not just the front plugs. If one of the plugs you changed was "ate away", that'* pretty bad. Probably more issues on the rear plugs. Only changing half of them could make it worse.

Metal in fluid on the dipstick means much more metal everywhere else and in pan. Fluid turning to a different color in a short distance is really bad. Transmission is probably about to give up.

This stuff is the least of your worries.

Pick a problem and lets work on it.