Car question? Mass air flow sensor or O2 sensor?

Just a suggestion; I believe that when you start the vehicle it is in open loop condition, meaning the fuel mixture is rich...same as the old choke mode with a carburetor. As far as the shifting issues, you may want to see if this is a electronic control transmission. From were I am sitting...I would surely start and make sure you have a Clean fully charged battery. Test the voltage when you park the vehicle at night and check it again in the morning with a simple digital volt meter..$15 or less at walmart. You have described a problem in a cold start condition. Test the voltage....check the trans fluid level HOT, not cold. And I will assume if your vehicle has a Hot air tub entering the air cleaner..it is there? And of course...check all the simple things first. Before you condemn the hardware! Good Luck Goodn!

When you say hesitation, is the engine losing power? If the problem is isolated to the transmission, it would have nothing to do with the MAF or O2 sensor. Is the transmission fluid dirty? If it is, have it flushed. If it's VERY dirty, have the transmission filter replaced as well. This won't undo any damage, but poor fluid condition does sometimes cause transmissions to malfunction in cold condition. Outside of that, it would be time for a rebuild.

I agree with all of the transmission answers. In my 88 Corvette I was having similar issues, and I had been chalking the slow shifting to an old transmission in a seldom used car. I finally remembered to check the transmission fluid level (duh) and it was low. I filled it to the right level and that improved drive ability substantially. I suspect changing the trans filter and/or checking the valve on the transmission will also make improvements, things I haven't done yet. If I recall correctly and MAF is a pretty pricey item and would be my last course of action. Also as noted a faulty MAF or o2 sensor should throw some codes. At any rate, I believe the O2 sensor (which can go intermittent and not throw codes rarerly) is relatively cheap, and usually not too hard to do, although you may need to buy the special split socket to do the job. A final point is there may be a vacuum leak in a system that is bypassed once the engine is warm, so check all your vacuum lines (spray carb cleaner near them, if they are leading the engine will speed up). Good luck

is your check engine light coming on? if it was 1 of those things then it should throw a code. sounds more like the transmission filter needs changing.

Sounds more like you need to get trans. service. Is your check engine light coming on? Would be on with sensor problem. G luck.