just had car rollin roaded and ive been told air fuel mix is to week. also engine manegment light comes on when i put my foot down in 3rd 4th n 5th and fuel cut comes in help what to do??? was recomended piggy back ecu n re map? got bout £700 to spend n e idears. mods done frount mount, cat back exhast,dump valve n lowerd on 15"s. runs 140bhp at 13psi.