Fault Code 51, Tester Code 28

1. Locate ECU behind passenger side of instrument panel.
2. Check continuity between lambda sensor connector terminal and ECU terminal 24. Also inspect sensor wire to ECU for damage and sensor connector for corrosion.
3. Inspect intake and exhaust manifold for leakage. If leakage occurs around lambda sensor, replace sensor seal.
4. Locate and remove lambda sensor from exhaust pipe. Inspect sensor for damage and/or combustion deposits and replace as needed.
5. Connect lambda sensor tester to sensor connector. Clear codes, then start and run engine until operating temperature is achieved. With engine at idle, sensor tester should read 450 mV.