Have a 2004 CRV that the engine shudders and cuts in and out only at about 2800 RPM going up hills. Doesn't do it at any other RPM below that or even at that RPM on flat road.
Has a P1457 EVAP code and a second code that just says N/A.
Any thoughts?

 

Assuming its not a misfire ( no misfire codes) its possible the torque converter clutch is chattering ( slipping on partial engagement) . Try a drain and refill of the trans oil. If its contaminated you may have to repeat the drain and refill 3 times.

 

What code reader is it? Does it do it as well in d3?

 

I had an issue with mine where something called the "knock sensor" had gone bad. It was causing me to shudder and lose power going uphill, almost rolling backwards on mountain roads. Might be worth a check. Pretty cheap and easy to take off but requires a rather large socket.