O2 Sensor Plug And 4X4

[98Rig]

so had a new engine put in my 92 exploder a few weeks ago and as i was looking around today i found that i have only one o2 sensor but two plugs. one is pluged in and the otherone is not but is super clean on the inside of the connector. would thier be a problem if the wrong plug is hooked up? also trying to diagnose my 4x4 not working and reailzed when i was driving at night the that green 4x4 and low range backlighting doesnt even light up. i checked all fuses and thier good the 4x4 module in back works fine, im assuming that the switch may possible be bad, anyone know wires colors at the switch that i can test for power?

 

[little x]

Your truck would throw a CEL if the O2 sensor weren't plugged in correctly. Where is this extra plug? Can you take a pic? Sorry, I don't have the wiring schematics.

 

[Spdrcer34]

In 1991 and 1992, they only used 1 O2 sensor. Starting in 1993, they started to use 2. If your ECM is still a 1992, it doesn't even KNOW to look for a 2nd O2....

Ryan

 

[98Rig]

its a 91 teh other plug it litterally on the same harness going down to the 02 sensor and it about 12 inches from the end of the plug and looks like the same exact plug.

 

[irloyal]

California Emmisions required O2 sensors before and after the cat-con I believe.