Engine Performance problem
2000 Mercedes Benz SLK230 4 cyl Two Wheel Drive Automatic 94000 miles

FLASHING FUEL LIGHT WHEN IDLING SOMTIMES.

CODE P0455 COMES ON WHEN IDLING SOMTIMES.

I CLEARD THE CODE MANY MANY TIME BUT IT COMES BACK.

I HAVE CHECK ALL EVAP LINES
I CHANGE THE GAS TOP

SOMETIMES I CAN DRIVE 150 MILE BEFORE LIGHT OR CHECK ENGINE
SOMETIMES I CAN ONLY DRIVE10 MINUTES BEFORE THE LIGHT OR CHECK ENGINE LIGHT COMES ON