Nissan Repair: 2000 Nissan Sentra, air flow sensor, throttle position sensor

Question
The codes comming up are P0100 and P1446.  The mechanic has checked several things involving the fuel air mix.  He also took the gas cap off to see if there was a vapor lock problem.  He checked the fuel for water, cleaned everything, he said the fuel pressure was between 35 and 45. He deletes the codes and road tests and as soon as the car starts to die the codes pop back up. He also has traced all the electrical wires and connections involved with these codes. I gave him your earlier response to my question and he said he would check the coil.  He also said the exhaust from the engine was getting red hot so he took the converter off to see if it was stopped up but there was no problems with it.  Any Ideas?  Thanks.
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-----Question-----
The car just all at once started dieing going down the road.  Sometimes it will run a few miles and die other times only a few hundred yards. One mechanic check it with a computer and said it was the air flow sensor but said it had to be taken to dealership so they could program the new sensor.  Another mechanic checked it on the computer and said it was the air flow sensor and a throttle sensor.  He replaced both and called nissan dealership and they said the air flow sensor didn't have to be programed.  It is still having the same problems. Another nissan service center says it does have to be programmed.  If so where do I get the codes?  Can the codes be deleted? Or is there anything else I can check?  Thanks.
-----Answer-----
Jerry,

Autozone or Checker can read the codes for free.  No, the air flow sensor does not have to be programmed and neither does the throttle position sensor.  The coil might be the problem you are having since 2000 Nissan cars had issues with coils.  You can also erase the codes by disconnecting the battery.  If it were me I would get the codes checked and email me back with what they are and we'll better define what you have going wrong.

Answer
Jerry,

The first code is the mass airflow sensor.  I bet the one he put on was defective from the box.  The second code is the evaporative canister purge valve being stuck closed.  There is a box that holds the gas vapors from the gas tank and that would need to be replaced.  I have seen several of these.