I have a 2000 With the V-10. replaced plugs and coils, fuel filter, trans service. Several weeks later i'm getting misfire and error code P0353. I know it is for coil #3 but I had it checked and its is fine. I dropped it off to my mechanic and he is unable to determine what the porblem is. Has anyone had a similer problem and did you find a solution.

 

You have an issue in your wiring harness. Check the wires going to the #3 coil connector.

 

I had a similar problem shortly after cleaning the engine on my 2000 F250 V10. It began to misfire and eventually set the P0353 and P0303 code. I knew I had gotten water and cleaning solution somewhere where it shouldn't be. I expected to find water in the spark plug cavity when I pulled the plug but finding none my focus turned to the #3 coil. I examined the boot, spring, and contacts. In doing this I discovered that one of the small contacts had a thin layer of oxidation on it. I cleaned it with a small dental pick and did the same with the wire plug that its attached to. I pulled a second coil off and using an ohm meter compared the readings. They were the same so I figured the coil was still good. Just in case, I marked the potentially bad coil that I cleaned, swapped positions with the known good one, and cleared the codes. No more misfire. I'm going to put a little dielectric grease on all of the coil connectors and that should finish the job.