I have a 95 Contour 2.5 V6 115,000 miles with an allusive problem. What is funny is it passed the TX state inspection a day earlier! They ran it on a dyno. Starting cold it runs fine, but as it warms up, a miss develops. It threw a code once - 173 and 177 - rich bank 1 & 2. The problem went away for a week and came back last night. Fuel pressure is 30 at idle and 36 when the vacuum is off. Sometimes it has the miss at idle and sometimes it only misses only in overdrive under load. Yesterday the engine ran perfect. I stopped for a few hours, restarted, and upon leaving the subdivision, the miss came back. I had other problems with the engine last year so I did a upper and lower manifold rebuild (all the gaskets) to get rid of a vacuum leak. The coil pack, wires, plugs and O2s were replaced within the last 6 to 8 months. I cleaned the MAF because when it's dirty it will make it run rich - that didn't fix it. I would replace all the injectors but they are real hard to find for this engine. I had one go out last year.