I have a 95 nissan sentra with a 1.6. The car has had the engine replaced and has about 125k on this engine. It all started when I was cruising to work the car died on the highway. I had it towed. I started checking and the plugs were burnt. I replaced them and it ran OK for about a month, then it started giving me problems again. I replaced the Distributor cap and rotor. I have had to move the distributor counter clockwise to keep it running. If I move the distributor to the original spot the spark plugs get gas fouled and I have to remove them to get it to restart. After running for about ten minutes it starts randomly missing at idle and stalls and also it randomly bogs when I step on the accelerator like it is starving for gas. I have replaced the temperature sensor. It had given me an O2 sensor error a few times so I replaced it and that did nothing. I tried cleaning the MAF with carb cleaner. Also one very strange thing was that the car was using about a quart of oil a week, 500 miles, has no leaks and no smoke. Any help is much appreciated.