ok, so i am having the same engine problems i was having a while ago. while in any gear, even N and P, it is surging, but not in rythm. its very sparce. when i press on the gas pedal to get her moving, it sputters a bit, but after about 2 seconds, kicks in and goes. when at highway speeds in D, i'll press the gas pedal, it sputters, and then has to take time to get going, like in idle. and the car is throwing a 51, any ideas?