This could be short for a vacuum leak in, say, a vehicle's fuel/air mixture inlet system or in the braking system of a train or a truck that uses vacuum-operated brakes.
check fuses and for vac leak at unit and vac pump
i have a vac leak my van feels like it missing when hook up to comp the code reads o2 sensor and vacume leak i need help
Yes, a vacuum leak will be detrimental to fuel mileage.
Yes
a vac leak
it could be a iac valve or a vac leak start with vac leak search if all vacum lines are right then turn to your iac idal air controle
probably a vac. leak check your brake booster
ckeck for vac. leak at brake booster
Solved it today. small vac leak at the air pump to the purge can.
With the car running, use a can of WD40 and spray all vac. lines, connectors, etc. When you spray near the leak you will hear the RPM's rise. That should get you in the ball park of your leak source.
bad iac valve or vac. leak
most of the time you can actually hear it . on stubborn ones hook up a smoke generator to the vac. hoses and pump the smoke into the line. If there's a leak you will see it.