I have a 2004 (new body) 4.6L 2v f150 xlt 2wd with a p0353 code after having unplugged a few things for a timing job. I have changed the coil, plug, connector and injector with no joy. I have read in the past that the magnetic field from the drier can disturb the current to the plugs and after much wire "wiggling" and insulation all around the drier I'm pretty confident that's not the case. I plan to open the harness up and trace it all the way to the pcm. The wires that run across the valve cover are very well insulated and wrapped and are flexible and not discolored at all, you wouldn't know they were 15 years old, but towards the the top by the pcm things are much more... crusty. Can anyone tell me which pin I'm looking for or where the fault likely is? I've read dozens of threads on primary/secondary faults but nobody ever reports back on what fixed it or if it was ever fixed.

 

https://www.obd-codes.com/p0353

 

I would double check the connectors to make sure you didn't bend a pin or mess up a connector.

 

I've definitely double and triple checked every inch of wire between the plug and ecu but the kicker is I didn't even have to unplug anything besides the coil itself to get the valve cover off.

 

Bump still looking for troubleshooting advice