My 2005 Ram with the hemi wouldn't crank over fast enough for it to fire, I finally got it to and a light in the dash that looked like two parentheses with a lightning bolt between them kept flashing and it was surging really bad (rough idle). I let it fully warm up and it still surged so I went to take it for a drive and I couldn't get it to go faster than 10 mph. I replaced the battery and puta bottle of heet in it and it's been fine for a couple days and now today it started fine but is doing everything else again. Light flashes, surges, won't go faster than 10 mph or 2000rpm. What is wrong?