[richtazz]

P0300- Random misfire.
Do the tune-up and clear the codes, let us know if it comes back.
P0336-CKPS circuit A range/performance error
Check the wiring from both of the CKPS's to the ignition module and PCM. These wires run close to rotating and hot components (harmnic balancer, pass side CV axle, exh manifolds, etc...) and commonly chaffe and or burn causing this code.
P1406- EGR valve pintle position error.
This code indicates the EGR was not in the correct position as per PCM command. It could indicate carbon build-up on the EGR pintle, a bad EGR valve, or a restriction in the EGR feed tube.
P1870- Transmission component slipping
Pretty much self explanitory. This code is set once the car reaches steady speed and the TCC is commanded to lock-up the converter. This indicates an internal trans issue, from a sticking valve, to dirty fluid, to bad clutches. If the random misfires are bad enough, it could "confuse" the PCM and cause it to lock/unlock the TCC tripping this code. Fix the random mis-fires first and watch for this code to return. If it doesn't, then the mis-fires tripped it and it's nothing to be concerned about.