I have a 1994 4.3 v6 s10 can I run it with no oxygen sensor hooked up or am I looking at major problems

It will start and run without the 02 sensor.
But will not run right.
And will cause engine and cat damage if run over a period of time unplugged.
02 sensor is a main part on controlling fuel mixture.

What is your problem on 02 sensor or why are you wanting to run it unplugged?
MY

I just put the motor in it and had the o2 wire routed around the crossover pipe (dont know why) and it got hot and started on fire now I dont know what wire is witch so I can splice new wires in ooh and there is no cat on vehicle

No cat is not good.
It is illegal to run it on a federal highway without a cat.

I would suggest you get a cat on it.
If just wiring on 02 sensor burnt get another 02 sensor.
Splicing 02 sensor wires is not a good fix.
They will draw moisture if not sealed up real good and cause more problems.

I dont understand that I know guys that have straight pipes or off road x pipes on mustangs or camaros I used to have a mustang with an x pipe and I had to buy a module on the o2 sensors because there wasnt any on it but ill try ro fix the one on the s10 I also have a parts truck so ill rob the cat off that:banghead: