3Rz connector help

Since i don't have a cat, it is okay to have it do nothing ? or could this prevent my engine from running?

 

I have a a/f ratio gauge that works in the cab, so maybe this is the orignal wire and the previous owner just connected the gauge straight to the o2 instead of locating the o2 wires in the harness

 

Depends. The factory o2 sensors are narrowband, where as 'most useful' a/f gauges are a wideband which displays an actual numeric value. Regardless, this plug disconnected will not prevent your engine from running.

 

The connector you've shown is different than my o2 connector. Perhaps they changed from year to year?
With the amount of oil on it, one would think it would burn off if it were connected to the exhaust.

 

I havn't had a cat for a while so the oil must of accumulated during the time it was hanging loose

 

Looks like the drivers side.

 

Hmm, my sensor is on the passenger side.