I put a new exhaust on and now its perfect. Nothing else done.

 

My car has been hesitating too, in the same way as you explained and only sometimes. Only mine has a slight chirping sound along with it. I changed the plugs/ wires, fuel/ air filters, cleaned MAF, cleaned connectors, cleaned throttle body, changed TPS cam pos. sensor and crank pos. sensor, checked for vac leaks and tested the coil pack and still no luck. Im still learning, I bought a haynes manual and its been useful