Black smoke

[01cummins6]

I have a 01 cummins was in a hurry this morning went to pass Someone and covered the road in smoke. Truck is bone stock straight piped.

[Me78569]

Check your map sensor.  It might be stuck reading a higher boost level.  Had this issue way back when.

[dripley]

It could be in the wiring harness also. Going thru similar issues now and did put in a new MAP sensor in. That did clear up a lot of my smoke down to a haze but still having a issue with the ECM not seeing the MAP occasionally. Pretty sure the rest my issue is in the harness. You could pull the connectors and clean them up, connect and disconnect them a few times. Then put some dielectric grease on them. 

Edited August 12, 2017 by dripley

[01cummins6]

Would unhooking it hurt anything if it's bad

[dripley]

Yes. The ECM needs it to control the VP. Someone else would have to explain that better than me. Mine has gone into limp mode when the ECM does not see it. 

[Me78569]

If you unplug the map sensor the truck will struggle to hit 50 mph.  nearly all of the fueling tables use boost as an axis for the map.