EPC problem with golf Mk4 2001

hi

i recently started my car up and was driving slowly in first gear, once i got out to the open road i notiched that my car wasnt goin above 3000 rpm, i stopped it and looked at the dash the EPC light was on aswell the exghaust managment light. i left the car off for about 10 mins and restarted it, it said emmisions workshop in red and it was fine again, does anyone know what could be wrong with the car i have a golf mk4 1.6 16v 2001

thanks for the help