I have a 1997 Lincoln Continental V-8, with 90,000 miles. For the last six months or so, the check engine light comes on but in a few days or hours it goes off. From time to time the car will not start. The car cranks when the key is turned but the engine won't start. My husband has checked the gas lines, replaced the fuel filter, the battery and even diconnected the battery to reset "things". And it usually starts, but this time nothing seems to get it going. Could it be the oxygen sensor or injectors? Please help. Thank you so much.