Code 86? Not P0086 or something like that?

87 for OBDI is: 87 Malfunction Indicator Lamp short Circuit.
-OR-
P1486 EGR Solenoid Valve Vent Open or Short.
-Or-
P1586 A/T-M/T Codification

There is NO such code as "86"... Keep in mind you car is an OBDII controlled car.

Here's a list of codes:
trouble codes

"Does this part need to be in there?"

1996 Dodge 1500 single cab / short bed, 5.9 4x4; 2" lift (springs not blocks), C.A.I and more mods to come.