Stubborn 93 Saturn SC2 with stalling, 32, 45 diag codes

Wonder if anyone else has ideas here, I'm about stumped!

I've got a 93 SC2, manual transmission, with 153,000 miles. It idles high (1300 RPM), but a check with carb cleaner spray didn't find any vacuum leaks.

The real problem is this. After the car is warmed up (10 minutes driving), I'll idle at a stoplight for a minute, then when I step on the gas, the engine sputters, the tach shows the RPM dropping, and the car stalls. Usually, if I just step on the gas lightly, the tach will drop a few hundred RPM for a second or two until something becomes "unstuck" and the the RPM rises above 1300. The worst was on a wet day, when it would stall unless the car was in gear. The error codes I get are 24 (VSS fault. = It stalled, duh!), 32 (EGR System Fault),

My first thought was "incorrect fuel/air mixture".

So far I've done (in order):

- Remove Throttle body, clean out with carb cleaner, replace Throttle Position Sensor (TPS) and Idle Air Control (IAC), reinstall Throttle Body with new gasket

- Replace Oxygen Sensor

- Replace EGR Valve (and gasket) and EGR Solenoid

Each time I've reset the error codes in case the PCM works differently with codes stored.

The car still does the same thing, though possibly not quite as often (hard to say). My Chiltons and Hayes books are about out of ideas as well. At this point the PCM is the only other thing I can think of.

Let me know your thoughts.

Thanks,