My car's been running bad and shutting down on me the past couple of weeks and didn't throw any codes but a few days ago it did. Got a P0320 (Ford Taurus) which is a generic code pointing to the ignition system. Great so I went got my meter and started poking around reading sensors, coils, wires, etc etc.
After all that I opened my trunk to get some rags out and I noticed a bag in the box. It was a set of new spark plugs and it was in there for a couple of years. Now I know what my problem is.
So today I went to work. Found all the plugs loose that I didn't need a wrench to take 'em out. I remembered that I used anti-seize compound on the threads to make the next job easier but it looked like it made it easy to work themselves loose. I didn't use it this time.
now my engine sound a whole lot better and the idle problem is over. YAY!
Now I'm laid up with bruised arms and a sore back. DUH!