p0430
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Toyota · SUVs
Catalyst System Efficiency Below Threshold Bank 2
Quick Answer
Error code P0430 on your Toyota SUVs means: Catalyst System Efficiency Below Threshold Bank 2. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Deteriorated catalytic converter on Bank 2 (V6/V8 models)
  2. Faulty downstream oxygen sensor (Bank 2 Sensor 2)
  3. Exhaust manifold leak on Bank 2 side
  4. Rich running condition on Bank 2 damaging the catalyst over time
  5. Contaminated catalyst from coolant leak via head gasket
How to Fix It
1
Verify no engine DTCs are present that could damage the Bank 2 catalyst
2
Monitor Bank 2 downstream O2 sensor readings for excessive switching indicating a failing converter
3
Inspect the Bank 2 exhaust manifold and pipes for leaks
4
Test catalyst efficiency by comparing inlet and outlet temperatures
5
Replace the Bank 2 catalytic converter if confirmed inefficient
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
Parts You May Need
Catalytic converter (Bank 2)
Downstream oxygen sensor (Bank 2 Sensor 2)
Exhaust manifold gasket
Exhaust pipe flange gasket
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