1996 GLE auto - when at a stop, my car idles at ~500 rpm (in gear) and occasionally hiccups - i tested my coils with a multimeter, and 3 are suspect, but all 6 passed the "unplug 1 by one while the car is on" test - all 6 made the car lope badly. the only code that i EVER got was bad knock sensor, and i was down on power. - i bypassed the knock sensor with a resistor, but still have the rough/low idle and bad mileage. i am getting a full set of 6 coils from mossy for ~380 including tax- any ideas for things i should do while installing the new coils? transmission recently rebuilt and working fine... someone had mentioned cleaning the intake, but since search is disabled, i cannot locate the details of this. something about a can of stuff that it sucks up and makes the car run better. I have 100,077 miles on the car at this moment, and brand new plugs. thanks for any response - s