Multiple fault codes usually results from some sort of system wide problem--such as a faulty harness, faulty ECU, or perhaps a power surge from a faulty alternator.

I'd reseat the ECU connector, as well as some of the connectors under the hood. Inspect the terminals in the connectors for any signs of "backing out"... if you know all connections are good, it's either the ECU or harness.

Verify charging system performance too--should be a steady voltage regardless of engine RPM, and it shouldn't exceed about 14.4 volts.

-Joe