OK, thanks quicklook2 and danr1. I didn't know they were all the same, that makes it much easier to read! I reread them and found these codes:

633 - 4WD switch is closed
116 - ECT out of self test range 0.3 to 3.7 volts.
636 - TOT sensor voltage out of self test range.
114 - ACT out of self test range 0.3 to 3.7 volts.
121 - Closed throttle TPS voltage higher or lower than expected.
637 - TOT sensor circuit above maximum voltage
638 - TOT sensor circuit below minimum voltage

I have some electrical cleaning solvent with a fiberglass brush, I'm going to take the PCM connector off and clean it thoroughly. I'll let you know how it goes.

Thanks again