problem with a 4.3 CPI

just replace the fuel injector and the return fuel line.still spuddering and blow out black smoke when I step on the gas.then when get down the road the service engine light comes on.code (45) O2 sensor indicates rich so I replace the O2 sensor still nothing.do I need to replace the evaporative charcoal canister or what do I need to do next.would highly appreciated if someone could tell me what it could be.

What year? what engine?? Just because you got a code does not mean that a sensor is bad. The o2 was doing its job by setting the code for rich mixture. Was the pressure regulator replaced also.
Fuel return lines pinched??

The CPI injector includes the fuel pressure regulator on the side of it.

Did you also replace the internal fuel lines in side of the plenum?

to blazerLT the injector and the return fuel line (that hooks to the side of the injector) yes

Those two fuel lines go to the injector.

One is to supply the injector with fuel, the other returns the excess unsed fuel back to the tank.

There is two of them and they come as a pair. They are called the "nut kit".

thanx Blazer LT

No pleblem, love to help.