i have a 1998 cobra with o/r x pipe, flowmasters, fipk, msd wires and coils. i am getting code p0171 which is bank 1 lean. the car feels like it has half the power it should, when hard acceleration it hesitates for about a second (it revs up but you cant feel any power for a second) it also starts to miss around 3k rpms. took it to the dealership and they said it was either the maf sensor or fuel pump starting to go. it has new plugs and a new fuel filter. any help woud be great. also when driving the car normal around town it feels fine. problems only start under hard acceleration.