93 altima running too rich

I have a 93 altima with 173,000 miles on it and it all of a sudden started to bog at idle and wants to die out. At first I thought it was a fuel injector but they are all ok. After checking the plugs they are all to rich. If you drive it is will be ok at higher rpms, but still feels slugish. And then at idle it will bog and wants die if you dont give it gas. Any ideas?

That has been happening to me lately also. My problem was the positive battery terminal. When it came lose, the current did not run through the fuses located on the cord. That was my whole problem. Something simple that just a few turns of the nut and everything was okay. Suggest trying that. I also had that same problem with my truck, the terminal was corroded and so were the cords. You can either clean the terminal by picking a terminal cleaner up at a gas station or hardware store for no more than ten dollars, or spend five minutes. May be something more than that or something less.