why does my car start idling extremely rough and wants to die after 20 minutes?

What is your question?

after driving 20 minutes or so or if i let the casr idele for 5 to 10 minutes the idle gets VERY ROUGH and engine starts clatteing and wants to die.. If i give it gas it will rev up and straighten out until i come to a stop again . It will start all over... I was told that the 2 cam or kam sensors are bad. would this cause this problem? I read where just because a code says the sensors are bad that it could also be other things such as drive belt or timing ? also when i got the car it had a slight ticking in the motor it has rapidly turned into a pretty noisy tapping like a loose rodcker arm sound. I recently had an oik change thats when i was told the sensors were out, could these sensors have anything to do with the noisy tapping.. ? it is REALLY Bad when I first start the engine before the oil is fully circulating.. The engine revs high upon starting for about 10 seconds and then it idles down to normal.. engine light is on....also. recently the battery in the remote door lock and unlock went weak or dead and the car would not go into drive, a friend showed me the bypass lever . I replaced the batery and that solved the problem but i noticed right away that the brake pedal is extremely soft since that incident. someone told me to disconnect the ground cable for 15 minutes and the computer would reset and solve that problem. I havent done it yet . would that do anything beneficial?