yes, very similar, even when in a gear... sometimes the surges are not as pronounced, as if the system detects them and tries to compensate... I just feel the change in the rotational frequency on the foot, when the foot is on the brake... when the car is in forward motion, i don't get to feel it... when the car is idling at a stop sign, i feel the change in engine speed under the foot, most times not enough to register on the analogue needle nor on the digital readout...

suspect air management - cleaned the MAF, waiting for new filter... can't hear any vac leaks but it doesn't mean anything... the CCV was torn, and no sound - besides, i am getting old, and don't hear nothing!!! lol...

planning on doing the engine flush and fuel filter change, as one of the other symptoms, the car lost its power on demand feature - when engine is relatively cold (5-10 minutes of driving from cold), and i need to merge onto a highway, when i hit the gas, it stumbles... besides pure embarassment - 4.8iS not capable of merging into traffic, it is outright not safe... i am there like a sitting duck, trying to go, and it doesn't go... lol...

so, flush, fuel filter, air filter... we'll see what happens next...