Rep Power: 0

changed front o2 sensor, plugs, plug wires ,cap ,button after that it ran good for about 4 weeks. Some times hard start & ruff idol

 
Rep Power: 0

sounds like the plugs aren't in the right cylinders when you swapped them out did you make sure to put them back exactly where they were? bc if not, that would definitely cause the problem that you're describing, if its not that, it sounds like a timing issue, make sure your timing is correct, and then from there i would honestly need more information to say whether or not it might be something else. but check those two items and make sure they are responding in proper order, and check the timing belt as well as the cams, and hopefully that will solve your problem.