2002 T-Bird wouldn’t start until OBD II was attached

[Stormshak]

2002 TB wouldn’t start. Found a blown fuse #17, Fuel Pump, still no start. Replaced Fuel Pump Relay, still no start.
Plugged in OBD II to run diagnostics and several error codes came up. The important one alluded to a bad Cam Shaft Sensor,?which I believe senses cam shaft movement and allows gas to the injectors. It made sense since it would turn over but wasn’t getting any gas.
Removed test equipment, turned the ignition key on and off times to see if I could here the fuel pumps energize and bingo, it starts.
Can someone tell me what hell is going on?

 

[Gus Gutz]

I believe it is CFM. Car f'ing magic. Did you by chance clear the code when you had the reader plugged in?

 

[donnyonee]

keep the reader in trunk

 

[Mach5]

I keep my reader plugged in all the time. Fire up the app on my phone (bluetooth!) when I want some more info about what's going on. (Currently a rough idle when waiting at a light in drive.)

 

[Stormshak]

I believe it is CFM. Car f'ing magic. Did you by chance clear the code when you had the reader plugged in?

Did not clear. And never gave CFM a thought....hmmm!