I have read some of these posts and I can't understand all these problems.
I have been a auto mechanic for 15 years its seems to me you are relying on the AutoZone to make a diagnoses, they just sell parts if you want a proper fix make sure you have the right disgnoses.
If you plan on working on your own car, you should have some kind of general knowledge on auto repair. Just remember your family rides in that car you just repaired, so it better be repaired correctly.. I you don't know how to fix it don't touch it.