WELL after throtle body clean its still there.

AT IDLE RPM'S GO DOWN THEN BACK UP WHILE IN DRIVE AT STOP LIGHT AND IDLING, NOT EVERY TIME. OTHER THEN THAT NO PROBLEM WITH ACCELERATION AND CEL NOT ON. AFTER ENGINE IS REALLY WARM IT WON'T DO THIS. INDY MECHANIC SAID DIDN'T DO IT TO HIM SO DOES NOT WANT TO JUST START REPLACING PARTS.

WHAT WOULD CAUSE RPMS TO FLUCUTATE AT IDLE?

SPARK PLUGS CHANGED 6 MONTHS AGO AND NOTICED IT AFTER ONE MONTH. CAN THAT DO IT.

1998 C 230.

HELP, TIRED OF PAYING THESE GUYS THAT HAVE NO IDEA, OR NO EXPERIENCE.