Mine idles a little rough as well. I was used to a very smooth and quiet idle in my 06 f150 and my wife's 06 grand cherokee. It seems to bounce just under 500 rpms. I guess its normal for these. I give up on mine. I got my check engine light fixed as well so I just deal with it. It runs great while driving so its all good for me.

 

Mine is the same way, idle is ok at one stop light, not so great the next, go figure. But it runs like a brand new engine while driving. New plugs, wires, cap, rotor. Seafoamed it.... Fuel injectors are all withing spec. I will just live with it. It has been like that for the last 2 years my mother and step father owned it, I traded my Dodge Ram for it a few weeks back(I have wanted an xj for the longest time).

I did pull a P0301 code, and a P0138 last week, reset them, and they have not come back. I may just R&R the upstream O2 sensor anyways.

 

Well here we go again. After driving it yesterday, and it seeming to be runnng fine. This morning I went out and started it up. Started fine as usual but, went to pull out of the driveway and it felt like the emergency brake was on. I could get the engine to rev to 2k but, the jeep just wouldn't go. I'm wondering if it had to do with that transmission code I got about the shift silenoid being bad. Check engine light is back on again. I'm going to see if I can find someone with a scanner to pull the code and go from there. I did notice also that one of the wheels was a bit warmer then the rest. I checked them after driving yesterday because I changed the front brakes and it just seemed a bit snug. I'm wondering if the caliper is sticking on that wheel which would cause it to feel like the E brake is on but, not sure if it would throw a code for it.
Anyone have any ideas?

Thanks again so much for all of your help.
This is one of the best sites I have ever joined.

 

I would be willing to bet that is the E brake feeling you are getting if a caliper is not releasing, had this happen to me once before.

 

Would it throw a code for the check engine light to come back on?
Just got to love it when people tell you they take care of things and don't. The guy told me he had recently replaced the upstream O2 Sensor but, when I went to take it out it was a pain in the butt