I have a 1996 F350 that I bought used a few years ago. It has a 460, and it started running funny just a couple of days ago. I drove it and stopped to get out. A few minutes later it surged and sputtered, like someone was tapping the gas pedal. It has done it a few times while I am driving it. The check engine light comes on and later goes off. I scratched up an old OBD I reader and got 565 and 512. I know that there is a vacuum line off of the canister which covers the 565, but I don't understand the 512 code. Any help is appreciated.

 

Continuous Memory DTC 512 indicates the PCM has experienced a power interrupt in its Keep Alive Memory (KAM) circuit.

NOTE:
If KAPWR is interrupted to the PCM, for example when installing a breakout box, or when battery is disconnected, DTC 512 may be stored in Continuous Memory.

A common code if some has disconnected the battery.

 

Wow. The only thing I have done to it is last week when I put in a new A/C orifice tube, accumulator, and charged it up with freon.

 

The the battery may have been disconnected some time in the past. Code 512 is from historical (aka Continuous Memory). Clear the codes, then drive for awhile and recheck.

How to clear CM codes: Start the code retrieval like you did before. When the codes are starting to display remove the STI connector from the reader.