Yes.
Also, you have a vacuum hose disconnected on top of the intake manifold. It goes from a hard line near the front to the "gas filter" on the top of the manifold.
Do a search on here for "94 O2 sensor relocation" or something like that and read through the threads where they move the O2...
That "cat" if that's what it is, appears to be left over from the diesel. Not sure how they differ in design or operation.
Did we determine that your engine is a 1994 1FZ-FE?
If so you should have two O2 sensors. The 94 engines had side by side cats, one for the front bank, one for the rear...
Yes, that's one of the wiring plugs for an O2 sensor. It appears melted and that will cause an issue.
O2 sensors are very sensitive with wiring. Check the harness and replace the parts and sections necessary.
Post a picture of your cats. You may need to take them apart to test if they are...