FixVault
Home › Cadillac › 2003 › CTS Automatic › Repair and Diagnosis › Engine Performance › System › Engine Controls - Troubleshooting - No Codes › Symptoms › Restricted Exhaust › Test Procedure

Test Procedure

  1. Did you verify the customers complaint? If yes, go to next step.
  2. Did you review the exhaust symptoms diagnostic information and perform the necessary inspections? If yes, go to next step. If not, check for any exhaust leaks.
  3. Is the system equipped with dual exhaust? If system has dual exhaust, see DIAGNOSTIC AIDS  . If system does not have dual exhaust, go to next step.
  4. Remove the HO2S that is in front of the catalytic converter. See HEATED OXYGEN SENSOR under SENSORS in REMOVAL & INSTALLATION - CTS article. Install the Exhaust Back Pressure Gauge in place of the HO2S sensor. Start the engine. Increase and monitor the engine speed at 2500 RPM. Observe the reading on the Exhaust Back Pressure Gauge. If the reading exceeds 1.25 psi (9 kPa) go to next step. If reading does not exceed 1.25 psi (9 kPa), go to step  8 .
  5. Turn the engine off and place the ignition in the lock position. Remove the Exhaust Back Pressure Gauge. Re-install the HO2S sensor. Remove the post-catalyst HO2S sensor. See HEATED OXYGEN SENSOR under SENSORS in REMOVAL & INSTALLATION - CTS article. Install the Exhaust Back Pressure Gauge in place of the post HO2S sensor. Start the engine. Increase and monitor the engine speed at 2500 RPM. Observe the reading on the Exhaust Back Pressure Gauge. If the reading exceeds 1.25 psi (9 kPa) go to next step. If reading does not exceed 1.25 psi (9 kPa), go to step  7 .
  6. Inspect exhaust system for damage in the exhaust pipe, debris in the exhaust pipe, muffler or resonator internal failure, or 2 layer exhaust pipe separation. Did you find and correct the condition? If yes, go to step  8 .
  7. Replace appropriate catalytic converter. After repairs are complete, go to next step.
  8. Remove the Exhaust Back Pressure Gauge. Reinstall the applicable HO2S sensor. See HEATED OXYGEN SENSOR under SENSORS in REMOVAL & INSTALLATION - CTS article. Clear any codes. Road test the vehicle in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step  2 .
About FixVault