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
Differential Pressure Feedback Electronic Sensor circuit Upstream Hose
Upstream Oxygen Sensor Circuit Slow Response (Bank 1)
Trouble code P0306 means:Cylinder 6 misfire detected
Trouble code P0442 means:Evaporative emission control system leak detected (Small leak)
It probably means something bad...
Gear ratio error in first gear.
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.
P0500 is loss of vehicle speed signal. You need to test the speed sensor.