Various drivability problems can be caused by vacuum leaks. This engine has plastic tubes that become brittle and crack over time. These tubes can be replaced by normal vacuum hose but be careful when changing the Tee fittings or hose connectors because some have built in restrictor orifices (usually color coded). If the restrictions are missing, drivability problems will most likely result.
Car Problem Reports
Dodge Dakota Vacuum Leaks Caused by Cracking Plastic Vacuum Tubes
Dodge Dakota Problem
Exhaust & Emissions Affected: 2.5L 4 Cylinder
Average Mileage: 125,448 mi (53,000 mi - 197,896 mi)
Vacuum line going to PVC was cracked at intake
Visitor, 1996 Dodge Dakota, 53,000 mi
Codes indicated " stuck in lean " replacement of oxygen sensors did not clear fault. CO% was high on emmissions test. Mechanic found vac leak and repaired.