Toyota Repair: 2000 Corolla Idle Problems, mass air sensor, sensor replacement

Question
I have a 2000 Corolla 5 speed that idles very rough at cold start almost to the point of quitting, but eventually goes away after several minutes.  The check engine light came on so I took it to a mechanic who said that is was a faulty Mass Air Sensor.  I replaced and the problem is a little better.  Before the sensor it stalled on accelleration but now after the sensor replacement it just stalls on cold idle.  I was wondering if you had any suggestions as to why is goes away when warmed up?  It doesnt seem like a noise from under the hood it is just the rough idle.

Thanks
Austin

Answer
I need to know what the trouble code was at the time the check engine light came on, check the invoice when the MAF was replaced to see if the code was listed on the repair order, I really need to know this in order to help, you can contact me directly at tedrttr@yahoo.com