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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 147 (Engine Control System - Trouble Shooting - No Codes) >> Symptom Diagnosis >> Restricted Exhaust >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify the customers complaint. 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 no, go to SYMPTOMS - ENGINE EXHAUST  under SYMPTOM DIAGNOSIS.
  3. Is the system equipped with dual exhaust? If yes, go to DIAGNOSTIC AIDS  . If no, go to next step.
  4. Remove the HO2S that is in front of and closest to the catalytic converter. Install the Exhaust Back Pressure Gauge (J 35314-A), or equivalent, in place of the HO2S sensor. Start and run the vehicle. With the engine idling at normal operating temperature, record the exhaust system back pressure reading on the gauge. Does the reading exceed 1.25 psi (8.6 kPa)? If yes, go to step  6 . If no, go to next step.
  5. With the Exhaust Back Pressure Gauge still installed, increase and monitor engine speed to 2000 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed 1.25 psi (8.6 kPa)? If yes, go to next step. If no, go to step  9 .
  6. Turn the engine off and place the ignition in the lock position. Remove the Exhaust Back Pressure Gauge. Re-install the HO2S sensor. See HEATED OXYGEN SENSOR 1 or HEATED OXYGEN SENSOR 2 under ENGINE SENSORS & SWITCHES in REMOVAL & INSTALLATION - 1.8L VIBE article. Remove the post-catalyst HO2S sensor. Install the Adapter (J 35314-A) in place of the post HO2S sensor. Start and idle the engine and monitor the engine speed to 2000 RPM. Observe the exhaust system back pressure reading on the gauge. Does the reading exceed 1.25 psi (8.6 kPa)? If yes, go to next step. If no, go to step  8 .
  7. Inspect the exhaust system for damage in the exhaust pipe, debris in the exhaust pipe, muffler internal failure or 2-layer exhaust pipe separation. Repair as necessary. After repair, go to step  9 .
  8. Replace the catalytic converter. After repair, go to next step.
  9. Remove the Adapter and reinstall the HO2S sensor. Clear any codes. Road test the vehicle to verify the repair. Did you correct the condition? If yes, system is okay at this time. If no, go to step  2 .
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