Trouble code P0701 means: Transmission control system,range or performance problem
P0340 is error code for Camshaft Postion Sensor Circuit Malfunction
it a transmission slipping code
Trouble code P1504 means:Idle air control IAC circuit malfunction
I noticed that question has already been correctly answered by Jrc405 on page 5 of the Ford Ranger XL Q & A
Trouble code P0306 means:Cylinder 6 misfire detected
Upstream Oxygen Sensor Circuit Slow Response (Bank 1)
Differential Pressure Feedback Electronic Sensor circuit Upstream Hose
Gear ratio error in first gear.
It probably means something bad...
Trouble code P0442 means:Evaporative emission control system leak detected (Small leak)
The P stands for the Powertrain. The 1 stands for Manufacturer specific. The 4 stands for Auxillary Emmission Control System. The final 0 & 1 ( as 01) identifies the section of the system that is malfuntioning.
Trouble code P0440 means:Evaporative emission control system malfunction