Checking for air leakage in exhaust system: Check

Fig 1: Checking Exhaust System For Leaks Between Cylinder Head & Rear Heated Oxygen Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

Check exhaust system by spraying a soap solution on all joints and connections between cylinder head and rear heated oxygen sensor (HO2S).

Only very small and slow bubbles are permissible.

Install tail pipe on exhaust system after check.