Mercedes Benz repair: delay respond to gas pedle, throttle position sensor, obd code reader

Question
Hello, I have a 1999 ml320 engine starts good. runs good. I just replaced all spark plugs. when I step on gas, the engine take a few seconds to respond,and the engine speed do not correspond to gas peddle position.The OBD code reader send out fault code P1542 any idea what it means please help. Thanks

Answer
your throttle position sensor potentiometer it is the small black box has 4 pinsand is usually sealed.it also could be your pedal value sensor your best bet is to take off your aircleaner check your linkage that goes to your throttle body make sure all is good while car is running pull linkage towards you to chack throtle body ..then if it is good by your linkage then it would be by your pedal they have a kickdown  switch by the foot pedal replace that