'Sup all. My 2000 2.7 was shuddering really bad when I first got it, then I replace the right cylinder head and that fixed the problem. Now the newest issue is the car stalls out when I stop for red lights. Sometimes it feels like it wants to stall then I give it some gas and it picks up again. Other times when I am giving it a bit of gas at around 35-40 mph the car surges. It isn't throwing any codes and I just replaced the spark plugs (recommended -Champion platinum) . Any ideas you guys could give would be appreciated. I was thinking o2 sensors (4 right?), maybe the map sensor or even the cam shaft sensor.