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OBD-II Code · Emissions

P0431

Warm-Up Catalyst Efficiency (Bank 2)

medium severitySafe to drive$100-$2,000

Bank 2 pre-cat efficiency low.

Common symptoms

  • CEL

Likely causes

  • Aging cat bank 2
  • Exhaust leak

Where to start

  1. Try the cheapest cause first. Start by checking: aging cat bank 2.
  2. Cost & scope. $100-$2,000
  3. If the code returns after the fix: escalate to a shop or scanner with live-data and freeze-frame. A code that re-sets means the underlying fault is still there.

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