This is what i've found out. On my car, the stuttering is related to rpms. You guys already know that. but i've also found that the stuttering eases at 3500-4200 range. this is where we have the most torque. Something else i've found is right when i start my car up, the car idles perfect, no stuttering. when i push on the peddle a little bit, up to around 2500, and leave it there, the idles will fluctuate about 500 rpms without me moving my foot. they will just go up and down until i let off or push it in farther. The hesitation usually occurs when the car is under a heavy load, and instead of giving that growl noise when accelerating, it just bucks, hicups and hesitates. If i go up a steep hill it will always hesitate, unless i can downshift and get it into that max tq rpm range. if its over or below that range it misses. I have extreme power loss when like this. You guys probably know that point in the peddle, the last little bit that when your in 5th gear, trying to pull a hill, the last bit of the peddle makes no visible difference. I can floor it and the rpms will slowly go up. and then i can 3/4 throttle it and they will go up at the same speed. but the only difference is that when i'm WOT there is hesitation, at 3/4 there isn't. So i'm thinking airflow also plays another part. I'm going to check all my battery connections, test my copmression, get new plug wires and see what i find. If anyone else expieriences these same symptoms let me know what you think. This is a mild/serious problem with us 420a 2g's, and am wondering if it has something to do with the ecu. anyone running a howell ecu got these problems?