Thanks for the input, I'll be adding bungs to tonight
There is a way to make a downstream o2 sensor simulator yourself, you will need to make two if you go this route. You have two different options on how to make it, either with an o2 sensor connector/pigtail (easy to hide with a ziptie on top of the frame) or cut the signal wires from an o2 sensor that has a working heater (you will need to weld bungs so you can mount it to the exhaust)
You will need:
-Wire Strippers / Crimpers
-Two o2 sensor connector pigtails OR two downstream o2 sensors that still have a working heater
-Two
4.7 microfarad capacitors (C1 in diagram)
-Two
12 Ohm Resistor w/ a minimum rating of 15 Watts (R1 in diagram) (if you use a pigtail)
-Two
1 Megaohm 1/4 watt resistors (R2 in diagram)
-Soldering Iron Kit
-Marine Grade Butt Connectors, Heat Shrink Tubing, Electrical Tape, or whatever is your preferred method of weather proofing (I don't want to argue with people about this... so just do it right.)
You must be registered for see images attach
Look at your o2 sensor harness connector coming from the ECM
A - TAN (bank 1) or TAN/WHT (bank 2) - Signal ground
B - PPL (bank 1) or PPL/WHT (bank 2) -Signal
C - BLK - Heater Ground
D - PNK - Heater V+
Aftermarket o2 sensor connectors, depending on the brand, will have different colored wires than the trucks wiring harness so you will need to take note of what A, B, C, & D matches to on the o2 sensor pigtail.
SIGNAL WIRES:
-Strip the middle of wires A & B back about a half an inch
-Take capacitor (C1) and twist the negative side of the capacitor (there will be a white or gray stripe with an arrow pointing to negative conductor - picture of example below) to wire A, and twist the positive side of the capacitor to wire B.
You must be registered for see images attach
-Strip the ends of wires A & B back about a half an inch and twist each end of resistor (R2) onto A & B
-Solder and seal all connections
HEATER WIRES (if you use the pigtail option):
-Strip the ends of wires C & D back about a half an inch
-Twist wires C & D to each end of resistor (R1), Polarity does not matter for this.
-Solder and seal all connections.
-Plug It In, Plug It In!
I cannot post links so you will have to copy and paste to amazon
Capacitor:
BOJACK 5X11mm 4.7uF 50V 4.7MFD 50Voltage ±20% Aluminum Electrolytic Capacitors(Pack of 10 Pcs)
12 Ohm Resistor:
LM YN 25 Watt 15 Ohm 5% Wirewound Resistor Electronic Aluminium Shell Resistor Gold (Pack of 2)
1 Megaohm Resistor:
25EP1141M00 1M Ohm Resistors, 1/4 W, 1% (Pack of 25)