VW POLO 1.4 SUDDEN LOSS OF POWER?

HI - I HAVE PROBLEMS WITH MY 2002 VW POLO 1.4 PETROL - THE EMISSIONS LIGHT STAYS ON AT ALL TIMES AND THE CAR SOMETIMES COMPLETELY LOSES ALL POWER ALTHO ENGINE STAYS ON BUT NO REVS KICK IN...IF I SWITCH ENGINE OFF AND THEN RESTART - EVERYTHING IS BACK TO NORMAL ALTHO EMISSIONS WARNING LIGHT REMAINS ON AT ALL TIMES. - VW DEALER DID DIAGNOSTIC AND SHOWED NO FAULT ! - THEIR ADVICE WAS TO IGNORE WARNING LIGHT ! - I HAVE PLACED BLACK INSULATION TAPE OVER THE ANNOYING WARNING EMISSIONS LIGHT! - SEARCHED THE FORUMS ON THIS ISSUE BUT NO SATISFACTORY ANSWERS - LAST TIME I EVER BUY A VW POLO - THEY USED TO BE SUCH RELIABLE CARS - BUT THESE DAYS, MORE HASSLE THAN ITS WORTH - ANY HELP ON THIS PROBLEM WOULD BE GREATLY APPRECIATED ! - THANX EVERYONE OUT THERE! - :)