Why does my engine shake when slightly idled up

Alright thanks no the check engine light gas not come on yet it happened after I replaced some vacume and coolant lines from a wire that shorted out and caused a fire but not directly after I replaced about 3 hours after I was thinking there may still be a vacume leak somewhere or a damaged sensor don't here vacume leak the sensor is directly on the back of the engine behind the intake right next to the coolant line running from engine to heater valve ganna try and replace it