Jay I have a 98 SVT with 64k on the odometer. I purchased the car used and like you was plaged with the same codes for way too long. Like you I sunk a bunch of bucks and sought advace here. In my gut I felt that the problem was not one that I could throw money at to fix it. I looked at the pt# on the PCM and noticed that the code was not the same as the code on my door post. My door post said "R" the PCM pt# code was "F". I went to the local Ford dealership and they crossed the pt# on the PCM and said it was a "good" pt#. So I continued to throw money at the car. Then in my research, I found out that Ford had created a generic pt# (code "F"). I did some more research and found the correct pt#. The "good" pt# was not calibrated correctly for my car. I bought the "correct" PCM plugged it in and boom-bada-bing... no more codes and.. as an added bonus my mpg's improved! A new pcm is about 3 bills. I found the "correct" PCM at a bone yard (listed on this site)for 35 bucks. I would suggest that you seek help in getting the pt#. The parts guys from the Ford dealerships listed on this site know their stuff, use them as a resource, They know what the are doing and have reference to history (ie bullitens). To get the "correct" pt# you will need your VIN and the PCM code on the door post.
Good luck
