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Home >> Mitsubishi >> 2003 >> Lancer Evolution >> Repair and Diagnosis >> External Pages >> Different car >> Section 30 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0139: Ho2S2 Circuit Slow Response - Bank 1 Or DTC P0159: Ho2S2 Circuit Slow Response - Bank 2 >> DTC Confirmation Test (Using Generic Scan Tool)
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DTC Confirmation Test (Using Generic Scan Tool)

WARNING: This page is about a different car, the 2002 Nissan Maxima and 2002 Infiniti I35. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Use the following test to check overall function of HO2S2 circuit. During this test, 1st trip DTC may not be confirmed.
  1. Start engine. Drive vehicle at a speed of more than 43 MPH for 2 consecutive minutes. Stop vehicle with engine running.
  2. Measure voltage between ground and ECM terminal No. 88 (bank 1) or No. 90 (bank 2) by backprobing. See Figure and Figure .
  3. While observing voltmeter, snap throttle to 4000 RPM at least 10 times. Voltage should change at a rate of more than .06 volt per second during this procedure.
  4. If voltage is as specified, system is okay at this time. If voltage is not as specified, go to next step.
  5. Let engine idle for 10 minutes, then measure voltage again. Or, measure voltage while coasting from 50 MPH in 3rd gear. If voltage is as specified, system is okay at this time. If voltage is not as specified, go to DIAGNOSTIC PROCEDURE  .
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