idle surges

I have a 98 GAGT 2.4 Every now and then right after starting the car and applying a little gas to move down the driveway the engine chugs rpms drop, then if you step on the gas real hard the rpms will stick at over 2000 and will slowly drop down to normal idle. This will happen when the engine is cold or hot. When the engine does finally stop choking I will get a burst of power that causes the transmission to thump. I have replaced the fuel filter, plugs, plug boots, tps, air filter, and cleaned the iat valve. Also checked it for pending codes as the engine light is never on, scanner showed no codes stored in memory. fuel pressure is good and cannot find any vacuum leaks.:uhoh:
HELP PLEASE has been this way for about 6months. Sorry about the novel here, but this problem is hard to describe. :banghead:

is this an auto or manual ?

Could be your trans or a wheel speed sensor messing with the tractoin control...

auto 4T60E