Sal... Appreciate all the info.
Bottom line here: all things point to the soldered extra wire I spliced into the Bosch Ox length of wires in order to extend them to reach the SSI bung. Discovery made (in thread) is those wires should NOT be soldered according to Bosch. Adjustments I made will be returned to the original settings. I'll disconnect the Ox and test drive the engine. If good performance, will check the milage. Ultimately I'll use a friends tail pipe meter to check the air fuel ratio.
You asked about the engine running on 6 or 5 cylinders. Rebuild was recently completed and aside from this milage issue and now the engine running poorly given my adjustments, there's no doubt all 6 are firing. That said, thanks for explanation in this regard.
Your offer to PM assist. Much appreciated / Thank you. I believe the situation's under "control" for the time being. We'll see if that bears out in a few days
