codes P0122 & P0452 on 2002 Pontiac Montana

driving down the road and engine dies, the gas gage goes to empty and get out of fuel light, the computor locks the engine out, dealer replaced alternator, battery, defective pins on back of instrument panel, dealer has a DVR plugged in to monitor for next time, already out 3 tow bills

The code P0122 is a Throttle Position 'low' code meaning that the Throttle Position Sensor is telling the computer that the gas pedal is barely pressed, when you are actully giving the car a lot of 'gas'. This can casue a dying problem. You also have a Code P0452, which indicates a fuel tank pressure sensor problem. Since you say that your gas gauge goes to zero a lot, it sounds like your fuel sending unit in the tank is defective. ( common on these vehicles ) or the harness to the sending unit is defective ( also common ) these are 2 areas to check
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how to fix toyota engine lights code po452
Have you figured out what was causing your stalling problems. I have the same codes and problems you described. Any help would be appreciated.

Thanks in advance
I replaced the TPS and Fuel unit inside tank, cleaned the wiring connectors and checked wire, still same trouble, Dealer had the van for 9 weeks off and on even had monitoring comp attached when it died. Just wasted good money. Resolved issue with a visit to a Honda Dealer. Just hope whoever got it didn't have it die and cause an accident. This was my wifes buggy, having her is a van that won't let her down is #1 concern. $30,000 could be a small price to pay.