code problem

IIRC, the motor should be warm before doing any of the tests (i could be wrong on that - too many cars to remember).

i dont have a CEL, so i have not used a paperclip and dont know. a scanner for 25 bucks could streamline it for you - the instructions are pretty explicit.
my two cents. good luck.

From your description, it seems that you did everything correctly.

The Key On Engine Off gets the codes in memory.

Running the engine with the jumper in will cause the CEL to quicky flash 4 and do the running self tests. It will dump only codes it finds with the Key ON Engine ON self test, it will not dump the stored memory codes. Only the codes it finds when it does the engine running self test will be displayed.

Code 23 - Throttle sensor out of range or throttle set too high - TPS needs to be reset to below .99 volts at idle. Keep in mind that when you turn the idle screw to set the idle speed, you change the TPS setting.

Code 34 EGR voltage above closed limit - Failed sensor, bad or missing signal ground, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the EGR valve by mouth. If you can, replace the EGR valve ($85-$95).

Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or air conditioning turned on. Possible neutral safety switch or wiring problem. You can generally ignore this code, since it has no effect on engine performance. It can affect the engine running self tests because of the extra drag on the engine.

that is what i was thinking. i had a car one time where it brought up a lot of codes and evertime i fixed something another thing would come up. it ended up being the prom to the computer.

The 4 flash is easy to miss.

The codes you got say that the computer is able to self diagnose & the fact that the engine runs would suggest that the computer is OK.