Checking the EGR System

Tests 1 - 4:

Tests 5 - 6:

SYMPTOM
CHECKING EGR SYSTEM

POSSIBLE CAUSES
- Vacuum line to EGR solenoid restriction or leak
- Vacuum nipple at throttle body plugged
- EGR valve assembly engine speed stayed same
- EGR valve assembly tone changed
- EGR valve assembly vacuum ≤ 3 in.Hg
- EGR valve does not hold vacuum for 30 seconds