Screeching from backend

I recently had my 2000 Chrylser Neon fixed (4 cyl., 16 valve, sohc, manual), i had to replace the both cylinders in the back wheels and replaced both tire rods in the front wheels. Now the car is making a very very loud screeching noise coming from the back end everytime i start the car after it has been sitting a couple hours. I do not know if this has anything to do with the new cylinders in the back end or what. PLEASE give me any ideas or advice as to what you think this screeching is, and how i can deal with it. Thank You.

loud noises from the back when you start it..

as in start the car? or start moving? if its starting the car, it sounds like a faulty fuel pump..? (idk if those screech?)

Thank you very much for replying, the screeching is when the car starts moving, it has nothing to do with engine or anything, the tires in the back end screech for the first 5 seconds, then no sounds at all for the rest of the ride, do u think i need new brakes in the rear? i just didnt think so because i didnt even replace the brakes in the front yet (ever), and they typically go quicker i thought (front wheel drive), they also screech sometimes, but all neons have the shitty brakes...<thanks in advance for any advice>

Is the noise when you start it, or when you start moving forward? If its when you start the engine, the common loud screech is an alternator belt that isnt snug enough. It screeches for a few seconds, until the alternator has recharged the battery for the energy it took to start the car.
If the noise only happens when you start moving forward, are you sure both rear wheels are turning, or is one of them dragging because its stuck, not turning. That will make a loud screech, until the car goes over some bump big enough to free up the wheel so it turns. This can be a stuck handbrake cable, or a brake that was assembled with something wrong.
With a front wheel drive car, it is possible to drive away with the rear wheels locked up - but if both of them are locked up, you will spin the car sideways when you start around a corner.
My favorite trick to hear what is going on under the car - is to drive along next to the wall of a tall building, with the window down. Any slight noise made by the wheels/axles will be much easier to hear.

the screeching isnt coming from the engine, it isnt a belt or anything, it is coming from the back tires, i will definetly check and make sure the back tires arent jammed, but it doesnt resist backing up or anything, is there anything that could cause that other then needing new brakes? thx