My max starts and idles well, accelerates well until ~2000 rpm and it begins 'lurching'. I back off on the accelerator until it shifts and I am able to accelerate further(in higher gear) until I get to ~2000 rpm, again the lurching. I back off once again and to get through it and once I'm around 40 mph (and less than 2000 rpm)I can maintain and accelerate. It always seems to happen at 2000. I am also pretty certain that I have a water leak into the inlet. Could it be and air flow sensor issue?