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Discussion Starter · #1 ·
With the OBD Link MX BT plugged in all the time, every 10 days or so my car develops a performance issue. My '16 FoST has 5k miles and has been to the dealership 3 times for the same problem.
My car will become sluggish, and weak. I will be making normal boost, but the timing will be so retarded that the car is slower than a Kia Rio, it surges and shutters and then is steady slow.
I will have 2 pending codes P0340 & P0344 which are Camshaft Position Sensor Circuit A and Camshaft Position Sensor Circuit A intermittent respectively. It goes away when you turn off the car and restart it.
Ford is having a hell of a time diagnosing it, mainly because after the issue occurs, I will call for a service appt and they will tell me to come in 3 days later, and the car is behaving normally.
I finally got a service adviser (tech wasn't available) to get in the car during one of these incidents, and they were able to acknowledge that I really have a problem.

They claim some scan tools cause interference, and they want me to leave my scan tool unplugged for a couple weeks to see if my issue ever returns. If it does not return they are going to claim my scan tool is causing the problem. It hasn't been long enough yet, but I wanted to put this out there.
 

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There is a TSB saying that scan tools plugged into the OBDII port can cause issues running a vehicle health report, so it is a possibility.
 

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Discussion Starter · #3 ·
Well it has been 2 weeks or more now since I have plugged in my scan tool; and I have not had any problems. Looks like it very could be the issue.
 

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Discussion Starter · #4 ·
I jinxed it! Car felt like a piece of **** again this morning, have not plugged in my scan tool in 2 weeks. Going in to Ford next week.
 
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