A slight pressure in the exhaust system is normal, but excessive exhaust back pressure seriously affects engine operation. Causes of high exhaust back pressure are dents/obstructions in the exhaust pipe or a plugged three-way catalytic converter/muffler.
Important: If the exhaust pressure exceeds specification, inspect for dents/obstructions. It may be necessary to disconnect the muffler or the pipe before or behind the converter and repeat the test.
Notice: Refer to Fastener Notice in the Preface section.
Important: Use non-silicon anti-seize compound on the threads. It may be necessary to use a scan tool to delete any codes set while performing the pressure test.
Tighten
Tighten the oxygen sensor to 45 N·m (33 lb ft).