1999 Honda Accord RPM Jump when step on gas pedal but car d

Hi!

Please help! I just changed EGR, Clean inside Manifold, changed sparkplug cable, Clean EGR Port, last few day it get hot here 97 degree, the car running fine for beginning then after 1 hour when I stop on the red light, and start moving the car I step on gas pedal and the RPM needle move to 2000 or 3000 RPM but the car doesn't not move until I hit on the gas pedal one or two times then the RPM start normal and the car could run fine. It is only happen when driving in local street low speed or 20-30 mph. It seem like the RPM idle does not stable and I don't know what wrong with please help any idea? Use ODB 2 scan code come out 0740 relate to transmission lock up solenoid valve. I don't know that cause the the problem?

Check engine light one but D4 light indicate does not come on. Thanks for your help