Perform Vacuum Test

NOTE: A blocked or restricted exhaust system usually results in loss of power or popping through the intake. Before proceeding with diagnosis, verify that condition is not caused by ignition or timing problems.

^ Visually inspect exhaust system for collapsed pipes, holes and cracks.

Replace any damaged components.

^ Attach vacuum gauge to intake manifold vacuum source.

^ Connect tachometer.

^ Start engine and observe vacuum gauge needle.

^ Gradually increase engine speed to 2000 rpm.

NOTE: Vacuum gauge reading may be normal when engine is first started and idled. However, excessive exhaust system restriction will cause vacuum reading to drop off while engine is idling.

^ Did manifold vacuum reach above 406.4 mm-Hg (16 in-Hg)?

YES -- No restrictions within the exhaust system. If sent here from Perform Emission System Malfunction Detection By Quick Test, Go to Check Test Equipment Calibration. Check Test Equipment Calibration
Otherwise return to Diagnostic Routines.

NO -- Proceed to Perform Vacuum Test - Exhaust Disconnected Perform Vacuum Test - Exhaust Disconnected