[smdempsey]

I have a '97 Park Avenue which has always had problems with the service engine light. I couldn't pass inspection for months because of this, but finally managed to get it to turn off for a couple hours using a fuel system cleaner. Now that I've passed inspection, the light is back on and the car idles and drives very rough. The light begins to blink on and off when I start the car at all now, and fuel efficiency is horrible. Is this strictly a misfire problem solvable by replacing plugs and wires? If so, is this difficult to do on my own and what are the best brands for replacements? I've heard that stock AC Delco are the best, but I've also heard that MSD's are good. Where can I find either of these at a reasonable price? I have had problems similar to this before and the error codes usually are misfires for which I had the wires replaced and it was temporarily fixed, at least the symptoms were, though the service engine light stayed on. I'm not sure if this is the same problem and I should just do the same thing or if it is something major that is making this a recurring problem. Thanks for any help anyone can provide.