FiTech EFI system

Update: Went straight at it after work..
With the O2 sensor unplugged, key on engine off n Displayed tach numbers on the handheld, plugged it back in, same test, back to random rpm tach numbers.
For my circumstance proof that the o@ sensor was interfering with the distributor pickup lines. ( who knows what affect that is having while operating.)

Applied Shielding to the O2 sensor wires from throttle body back to firewall, and now FINALLY no Tach numbers displayed with key on engine Off

Beside the shielding I already had on the Pickup module distributor line, I did not shield any other wires.

Short ride seems good, can't test it too much till after the weekend. I may just have a handle on this.

More to follow after additional testing.