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Exhaust System Check

  1. If On-Board Diagnostic (OBD) system check has been performed, go to next step. If On-Board Diagnostic (OBD) system check has not been performed, perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article.
  2. Remove heated oxygen sensor. Install exhaust backpressure tester in place of oxygen sensor. Start engine and let idle. If pressure reading is not 1.25 psi or greater on all models except 2.2L and 2.4L engine, or .5 psi or greater on 2.2L and 2.4L engine, go to next step. If pressure reading is 1.25 psi or greater on all models except 2.2L and 2.4L engine, or .5 psi or greater on 2.2L and 2.4L engine, go to step  4.
  3. Increase engine speed to 2000 RPM (3000 RPM on 2.2L and 2.4L). If pressure reading is greater than 3 psi on all models except 2.2L and 2.4L engine, or .75 psi or greater on 2.2L and 2.4L engine, go to next step. If pressure reading is not greater than 3 psi on all models except 2.2L and 2.4L engine, or .75 psi or greater on 2.2L and 2.4L engine, go to step  6.
  4. Check exhaust system for crushed pipe, internal muffler damage or heat distress. If problem does not exist, go to next step. If problem exists, repair as necessary and go to step  6.
  5. Replace catalytic converter. After repairs, go to next step.
  6. Operate vehicle within conditions under which original symptom was noted. If system operate properly, system is okay. If system does not operate properly, go to step  2.
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