car drops rpm's
 

my car has been doin some weird crap for the past two days. when i start it, (the temperature gauge needle is below the c), it idles fine in park, but when i shift into drive or any other gear, the rpm's will drop and the car will shake like crazy and/or stall out. i just dumped a couple grand in this car to fix it and im sick of this sh!t, but if anybody knows what the problem is id appreciate it
thanks

Check the engine coolant temperature sensor.
Clean the IACV valve and the TB.

o yea and once the car warms up, it drives fine... also, when needle is below the c and the car is not warmed up, if i tap the gas pedal, it will act as if the car was in neutral and just rev the engine (but the tranny is in drive), i have to push down prolly about 1/3 to 1/2 way on the gas pedal to get the car to go anywhere

i replaced the engine coolant temperature sensor a few months ago, and i cleaned the throttle body about half a year ago, i shouldnt have to clean it again this soon should i?

your tranny is slipping. A flush of fluids can possibly improve or fix that solution but a new tranny may need to be in your near future.

since you stated you just dumped a lot of money into the car recently, I'm assuming you had a very good tune up done?

a lot of parts are new under the hood. i recently replaced all 6 fuel injectors, all new hoses, new oxygen sensors, new pully, new ectc, new ecu module (there was damage to the old one), new belts, new spark plugs, and many others, basically everything needed to make the car run well i have done. i also drive my car relatively normal. i have good driving habits and i dont push on it, unless i am racing, which is very very seldom in the winter. how much would a new tranny cost me? i said to myself a while ago, if my tranny ever went then i would do a 5 spd conversion, how much would a new auto tranny cost me? i know a conversion would cost around 2 grand.
thanks