Code 43 is the knock sensor circuit. Could be a problem with the knock sensor, PCM, or PROM. Once again, you need a good diagnostic to determine which one of the three it is. Where did you guys match the code 43, the 93 service manual and the Chiltons both show knock sensor?
Here are a couple of helpers: The voltage between the knock sensor wire and ground should be 4-6 volts. The resistance between the disconnected knock sensor and engine block should be 3.3 to 4.5 kilo-ohms. Over 6 volts, means the wire is too close to secondary ignition wires. If it is not in-between the two resistances, it is likely a bad knock sensor.
I agree with you guys on the other ones. 34 is the MAF circuit. 66 means you have low freon. 67 means there is a problem with the cruise control switch on the turn signal, or possibly a problem with your brake switch for the cruise control. 67 needs a good diagnostic.
1999 540iA Sport
Former 93 SSEi Owner
Former 89 SE Owner