Here are the codes:
11 - Timing Belt skipped 1 tooth or more from initial learned value. Intermittent loss of either camshaft or crankshaft position sensor. No crank reference signal detected during engine cranking.
Code 11 may be your demon. Changing the PCM would eliminate the code but the timing belt may have skipped a tooth.
12 - Battery or computer recently disconnected - don't worry about this one
21 - Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably bad oxygen sensor
37 - Torque converter clutch solenoid CKT or park/neutral switch failure
43 - Multiple/Single cylinder misfire
21 and 37 should be addressed also. 43 may be a result of the skipped timing belt.