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DTC 425: Rear Ho2S

  1. Perform a compression check on all cylinders. See ADJUSTMENTS article. Repair as necessary. If compression is okay, go to next step.
  2. Check for air leakage in intake system. Repair as necessary. If there is no air leakage in intake system, check for air leakage in exhaust system. Repair as necessary. If there is no air leakage in exhaust system, check fuel and residual pressure. Repair as necessary. If fuel and residual pressure are okay, retest using new HO2S.
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