GMC Repair: truck is putting out black smoke, vacuum line, p0174

Question
I have a 2001 4x4 with a 4.6 motor.I recently cut the cat- inverters out .My problem is every now and then the truck loses power and the check engine flashes a few times and the black smoke pours out of it .It might happen a few times one day ,not very reguler...A friend checked the code and he thought?? that it was running lean on a couple of cylinders..It almosy seems like its flooding

Answer
Hi-
What was the code? p0174? or p0171?
I would check the fuel pressure rguulator (small round regulator located on the DRIVERS side fuel rail, underhood) Pull off the small vacuum line off the regulator, if there is ANY gas in that vacuum line, that is your problem.
Also if the converters were cut off  and NOT replaced, you may have the o2 sensore sending low readings to the computer, and the computer is trying to falsely enrichen the mixture.
Thats my best advice with information given.
Thanks
Pawl