So i have a 2004 grand cherokee overland and the past few weeks ive noticed a small RPM fluctuation while driving at any speed. Every now and then i can feel the jeep sorta lunge forward or backward. It also has a slight RPM fluctuation while at idle Could this be cause of an o2 sensor or TPS or something? Thanks

 

If there's fluctuation while driving and it's "lunging" then your transmission is slipping. If I'm right about the problem, you're going to have to replace your transmission which would suck. Other possible causes are a misfire, a bad 02 sensor, a PCM that needs to be reprogrammed, or even a bad TPS but the only way you'd have that is if you can press the throttle down all the way while driving and it not responding. Your best bet would be to take it to somewhere like autozone and have them run the OBDII scanner on it and see what comes up