1st step should be checking for codes
sounds as you have a bad misfiring and need to be checked
black smoke is unburned fuel /check it for tune up and if firing on all cyl.
post back your codes for more help

Answered by BMRFIXIT (expert)
19,736 answers provided

okay i went to autozone today and they put the scanner on it they didnt give me code numbers but said that the mass air flow sensor had too high a signal (whatever that means) and that there were other faults such as o2 sensor and cylinders not firing. I used some mass air flow cleaner on it and it didnt seem to make a difference.Conditions were worse today before even cleaning it. It was shifting really hard and sputtering even worse than yesterday at times i could only go 20 mph and i had to let allmost all they way off the gas to get it to go at all.also backfiring.any ideas?

Response from juggernaut615
13 questions asked