Idling problem on 2002 Liberty

I have been having a recent problem with the idling on my 2002 liberty.
At a complete stop with the jeep in drive you can feel the idling drop (almost like a sudden jerk) and see the rpm gage drop slightly but then recovers back to the normal range.
These symptoms do not occur when the jeep is in the park position and become worse and more suddenly when you have the A/C or heat on.
The jeep has never stalled during these idling dips.
It also seems this problem is causing a hesitation when at low speeds until in full momentum, then all seems fine.
I have noticed that on occasion, when you have to hard accelerate the jeep hesitates and the RPM climb higher than normal and the check engine light flashes for a few seconds and then resets itself. I am not sure if this problem is connected to the idling problem or has something to do with the transmission.
Any help in this matter would be greatly appreciated.
Thanks in advance.

it's a misfire, you may need a tune-up. I would recommend a compression test and if ok replace spark plugs>>> any codes?? check engine light??

I don't have a OBD scanner to check for codes but the check engine light started to flash constantly and then when to a solid illumination.

yes whenever your engine light flashes it's a engine misfire...

Thank you.
Replaced the spark plugs and disconnected the negative battery terminal to rest the computer and all is good now. Have more power and the trans shifts like it should.
A friend hooked up his OBD scanner and there are no fault codes stored in the system.
Liberty is running solid yet once again.
Thanks for all your help.

were glad it's fixed...