Well - I'm starting to get frustrated with this problem and have yet to figure it out.

1990 245 auto with 231k miles - the car runs well, starts up quickly in the morning in under one crank. I'm getting ~20 mpg in town and got 24.5 mpg last weekend on the highway. The car doesn't always like to re-start after being shut off and is still warm. It was, in fact, lots of fun on the Montana/Canadian border crossing when I tried to restart the car after turning it off to wait for the cars ahead of me to go through. I've checked, replaced or repaired the following parts in the past few months:

RPM Sensor replaced
ECT Sensor replaced
Fuel Injection Relay resoldered (clicks on and off with ignition application)
Fuel Injector seals replaced (car runs noticably poorer with any injector plug removed)
Throttle body cleaned & gasked replaced
IAC cleaned and tested
TPS adjusted
Air hose between AMM and throttle body replaced
Intake manifold gasket replaced
Air Filter replaced
O2 sensor voltage checked (fluxuated between 0.1 and 1.0v)
25amp fuse checked
Fuel Pressure Regulator - no fuel out the front, and decent flow on the return line
Bottle of Techron run through the system on a low tank

OBD codes being thrown are 2-3-2 & 2-3-1

I swapped the AMM off of my previous '92 244 into the 245 to no notable improvement. I was stuck with a longer than normal no-start this afternoon and pulled the plugs to clean them off - and there is no doubt that it's running a bit rich. What am I not thinking of?

Many thanks,
Zach