99 gmc jimmy rough running

I have a 99 gmc jimmy 4.3L 4x4. I
had a ringing light on saying to
replace o2 sensors. Not knowing
which sensor was bad, I replaced
all 3 sensors at once.
Immediately after doing this
change, I ran it around the block
and it started running horrible.
Check engine light came on again
and I could barely keep the engine
running. It felt like it was starving
for fuel. When I rev it, it just
stutters. Also I burnt a full tank of
gas in 2 days by only driving total
of 30 miles. I noticed a plume of
black smoke from the exhaust
when I accelerate. At best she will
do maybe 35 mph.and if I slow
down she almost shuts off. The
engine is running so rough you
can see it rocking.
I took it to the auto parts store
and they told me it was a ignition
code, so I replaced my ignition
control module, and the
distributor cap and rotator. These
made no difference at all.
I replaced my o2 sensors a
second time and the new sensors
I had just replaced were covered
with black soot.
I am at a loss now. Not having a
good scan tool.
Someone said maybe a spider
injector going bad? Idk..