Chrysler Repair: 2003 Chrysler T&C, very rough running and idle, signal circuit, sensor signal

Question
Hi Kevin,
My 2003 Chrysler T&C with 100,000 miles suddenly started running (and idling) very rough. It drives, but very poorly. It's like it's not running on all cylinders. It doesn't stall, but almost. The exaust smells strongly of sulfer dioxide. The OBDII code being generated is P1297 (MAPPC). I've replaced the MAPP Sensor, plugs and wires, to no avail. I can't see a conventional EGR valve. Any thoughts on the next thing I should check.

Thanks,
Mike

Answer
P1297-NO CHANGE IN MAP FROM START TO RUN


POSSIBLE CAUSES
GOOD TRIP EQUAL TO ZERO
MAP SENSOR VOLTAGE BELOW 3.19 VOLTS
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
MAP SENSOR
(K1) MAP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(K1) MAP SENSOR SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
MAP SENSOR VACUUM PORT
PCM