NHTSA Complaint #10579323 — 2004 HYUNDAI ELANTRA

HAVE 2004 ELANTRA W/ 77,000 MILES. CHECK ENGINE LIGHT CAME ON WHILE STARTING CAR IN AM. CAR HAS NO SYMPTOMS OF BAD PLUGS,02 SENSOR, OR CATALYTIC CONV. ISSUES. RUNS FINE, NO DIFFERENT. I HAVE THE CAR CHECKED DIAGNOSTICALLY AND THEY SAID THE 02 NEEDED CHANGING AND NEW P;LUGS / WIRES. THE WIRES/ PLUGS ARENT DUE FOR ANOTHER 30K MILES WE THOUGHT, AND THE CAR RUNNING FINE! WAS WAITING TO HAVE THIS SERVICE DONE AS WE WERE GIVEN A $613.00 QUOTE! IN MEANTIME THE CHECK LIGHT WENT OFF AND CAR RUNNING FINE! IT HAD JUST HAD THEOIIL CHANGED AND A NEW AIR FILTER WHEN THIS OCCURED, AND NEW GAS. IT SEEMED WHEN THE CAR WAS ALMOST OUT OF GAS( I LET IT RUN LOW) I PUT A BETTER GRADE FROM ANOTHER STATION AND THIS IS WHEN THE ENGINE LIGHT WENT OFF! WHY WOULD THIS OCCURE IF IT IS NEEDING PLUGS, 02 SENSORS??? ALSO NO TROUBLE, ROUGHNESS OR IDLE TROUBLE, OR POWER LOSS WITH THIS CAR. COULD IT BE BAD GAS, AIRFILTER ISSUES?? PLEASE HELP!! *JS