Suzuki XL7 2007 Service Manual page 954

1K-5 Exhaust System:
Restricted Exhaust
Special tool
J 35314-A Exhaust Back Pressure Gage
Diagnostic Aids
WARNING
!
Refer to "Hot Exhaust System Caution".
For dual exhaust systems a quick check of exhaust flow will help determine which side of the exhaust system is
restricted. The side that has less exhaust flow is the side that will be suspect, and diagnosis should begin there.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4.
The exhaust system has very low back pressure under normal conditions. If the exhaust system is restricted, a
significant increase in the exhaust pressure is noticed on the J 35314-A.
Removing the HO2S sensor may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
5.
This step will isolate the catalytic converter from the remainder of the exhaust system.
8.
Confirming that the condition has been fixed is essential. If the symptom still exists and the vehicle has a dual exhaust
system, proceed to step 2 and repeat diagnostic procedure on the opposite exhaust pipe.
Step
1 Did you verify the customers complaint?
Did you review the exhaust symptoms diagnostic
2 information and perform the necessary inspections?
Is the system equipped with dual exhaust?
3
1. Remove the heated oxygen sensor (HO2S) that is in
front of the catalytic converter. Refer to the
appropriate procedure. Refer to "Heated Oxygen
Sensor Replacement - Bank 1 Sensor 1: " or
"Heated Oxygen Sensor Replacement - Bank 2
Sensor 1: ".
2. Install the J 35314-A Exhaust Back Pressure Gage
4
in place of the HO2S sensor.
3. Start the engine.
4. Increase and monitor the engine speed at 2,500
RPM.
5. Observe the exhaust system back pressure reading
on the gage.
Does the reading exceed the specified value?
Action Value(s) Yes
— Go to Step 2
— Go to Step 3
Go to
—
Diagnostic Aids
9 kPa (1.25 psi) Go to Step 5
No
—
Go to
"Symptoms -
Engine Exhaust"
Go to Step 4
Go to Step 8