LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 258 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0420: TWC System - Low Efficiency >> Test Description

Test Description

WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic procedures.

  1. 2 -  If any component DTCs are set, diagnose those DTCs first. A malfunction in a component can cause the converter to appear degraded or may have caused the malfunction.
  2. 3 -  This step includes inspecting for conditions that can cause the TWC to appear degraded. Repair any problems found before proceeding with this test procedure.
  3. 4 -  If you need to replace the TWC, make sure that another condition is not present which would cause damage to the converter. Correct any possible causes of converter damage before replacing the TWC in order to avoid damage to the replacement converter.
scientia non olet · About LEMON Manuals