I had to put the 12Volt source feeding my Fog Lights on a Relay that got triggered from an under-hood source that was ON with the Engine Running and OFF when shut down.
I tested the wires in the Batch Connection fastened to the passenger side support arm running from the Strut Tower to the left of the front-left Engine Mount.

The PINK wire in that bundle showed +12V Off with the Engine running and stopped.
I took a feed from that Pink wire and ran it to my Relay to have it be the 12V signal to Close or Open the Relay depending on the Engine Running or not.

After connecting the LOAD to the LOAD Terminals on the Relay (Fused @ 10 Amps) I brought the tapped-into Pink Wire over to the Relay Triggering Terminal and Grounded the opposite Relay Triggering Terminal to where the Relay was fastened to the Passenger Side Fender, just to the rear of the Windshield Washer Fluid Filler Neck.

I haven't got the Fog Lights to come on with the Engine running.
Taking my wife into work, today, the Check Engine Light came ON and remained ON Steady.
AutoZone Read the Code for me.
O-2 Sensor Front Bank.

Would not reset the Light for me.

1. Did I tap into the O-2 Sensor causing the Light (Code)
2. Can I test the O-2 Sensor?
3. Go get a new O-2 Sensor because the Code has nothing to do with the Aux Lighting Tap-into. (Pink)

 

I'd say get a new o2 sensor

 

The Monte is back to NORMAL!
Turns out that I tapped into the O-2 Circuit and wound up blowing the fuse.
That's all. Just a Fuse!
AutoZone gave me the Code Reader for 45-Minutes to check-out the Circuit after the Fuse got replaced and the two Codes it was throwing went away.
Did a ERASE on the Oxygen Sensor Codes it was throwing and drove home with NO "Check Wallet Light" on.
Fuses cost me $3.00
Lesson learned; Priceless!

 

where is the fuse , which one of the many

 

 

It is in the bottom fuse box under the hood. It is in the bottom corner.