'91 200 20V TQ Dies on Freeway - Now Won't Start

[Michael Palatas]

It was a dark and stormy night....  My "4 month owned", IA Stage III
chipped, '91 200 20V TQ was running fine on the freeway at 70mph yesterday
when it started to shudder a bit and lose speed.  Pressed harder on the
accelerator - no response.  Had some slight, unusual vibration you could
feel in the steering wheel - almost like the engine misfiring - as it
coasted down to a stop.  Electrical indications normal.  Wouldn't restart.
Checked the fuel pump fuse - OK - so flatbed towed it home ($130).

Tried to restart.  Strong crank, but rough/unusual vibration as the engine
turned. Checked the following:

Fuel Pump Relay OK
12V at fuel pump connector
Fuel pump running during crank.
Pressure/fuel at fuel filter outlet
Distributor turns when cranked (but did find the wide tipped rotor - will
replace soonest).
Good spark on high tension wire.

Hooked up VAGCOM, cranked for about 5 seconds, and had the following code
readouts (and only these):

"00519 - IM Pressure Sensor (G71)
            06-00  :  Signal too high
___________________________________
00523 - Intake Air Temperature Sensor (G42)
           30-10  :  Open or Short to Plus / Intermittent
___________________________________
65535 - Internal Control Module Memory Error
            00-00
___________________________________
00537 - Lambda (Oxygen Sensor) Regulation
            08-10  :  Control Limit Surpassed / Intermittent
___________________________________
00525 - Oxygen Sensor (G39)
            29-00  :  Short to ground
___________________________________
00513 - Engine Speed Sensor (G28)
            27-10  :  Implausible Signal / Intermittent

Readiness:  N/A"

Any ideas/suggestions?  None of the codes sound too ominous to me, but I am
not a code expert.  Not sure why I would have the Oxygen Sensor faults -
just put in a new one about 2 months ago - car ran fine after that
replacement till now.

Mike in North Hollywood, CA