Code P2195, O2 sensor error

Good afternoon.

How does the engine run?

There are some possibilites for these codes. I have attached the flow chart plus some possible issues.

Roy

The A/F sensor provides output voltage* approximately equal to the existing air-fuel ratio. The A/F sensor output voltage is used to provide feedback for the ECM to control the air-fuel ratio.

With the A/F sensor output, the ECM can determine deviation from the stoichiometric air-fuel ratio and control proper injection time. If the A/F sensor is malfunctioning, the ECM is unable to accurately control air-fuel ratio.

The A/F sensor is equipped with a heater which heats the zirconia element. The heater is also controlled by the ECM. When the intake air volume is low (the temperature of the exhaust gas is low), current flows to the heater to heat the sensor to facilitate detection of accurate oxygen concentration.

The A/F sensor is a planar type. Compared to a conventional type, the sensor and heater portions are narrower. Because the heat of the heater is conducted through the alumina to zirconia (of the sensor portion), sensor activation is accelerated.

To obtain a high purification rate of the CO, HC and NOx components of the exhaust gas, a three-way catalytic converter is used. The converter is most efficient when the air-fuel ratio is maintained near the stoichiometric air-fuel ratio.

*: The voltage value changes on the inside of the ECM only.

HINT:
- DTCs P2195 and P2196 indicate a malfunction related to bank 1 the A/F sensor circuit.
- DTCs P2197 and P2198 indicate a malfunction related to bank 2 the A/F sensor circuit.
- Bank 1 refers to the bank that includes cylinder No. 1.
- Bank 2 refers to the bank that includes cylinder No. 2.
- Sensor 1 refers to the sensor closest to the engine assembly.
- After confirming DTC P2195, P2196, P2197 or P2198, use the hand-held tester or the OBD II scan tool to confirm A/F sensor output voltage (AFS B1S1 / AFS B2S1) from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL).
- The A/F sensor output voltage and the short-term fuel trim value can be read using the OBD II scan tool or the hand-held tester.
- The ECM controls the voltage of the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBD II scan tool or the hand-held tester.
- The OBD II scan tool (excluding hand-held tester) displays the one fifth of the A/F sensor output voltage which is displayed on the hand-held tester.

That does not give me any voltages for the sensors as the flow chart suggests.

Can you give me the voltages off your live data while running.

Roy

The long term trim at 51% is the key.

It is very lean.

You have either a very large vacuum leak, low fuel pressure or injector issue.

Roy

171

DTC P0171 SYSTEM TOO LEAN (BANK 1)

CIRCUIT DESCRIPTION

DTC Detection Condition
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The fuel trim is related to the feedback compensation value, not to the basic injection time. The fuel trim includes the short-term fuel trim and the long-term fuel trim.

The short-term fuel trim is the short-term fuel compensation used to maintain the air-fuel ratio at stoichiometric air-fuel ratio. The signal from the A/F sensor indicates whether the air-fuel ratio is RICH or LEAN compared to the stoichiometric air-fuel ratio. This variance triggers a reduction in the fuel volume if the air-fuel ratio is RICH, and an increase in the fuel volume if it is LEAN.

The short-term fuel trim varies from the central value due to individual engine differences, wear over time and changes in operating environment. The long-term fuel trim, which controls overall fuel compensation, steadies long-term deviations of the short-term fuel trim from the central value.

If both the short-term fuel trim and the long-term fuel trim are LEAN or RICH beyond a certain value, it is detected as a malfunction and the MIL is illuminated and a DTC is set.

HINT:
- When DTC P0171 or P0174 is recorded, the actual air-fuel ratio is on the LEAN side. When DTC P0172 or P0175 is recorded, the actual air-fuel ratio is on the RICH side.
- If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 or P0174 may be recorded. The MIL then illuminates.
- If the total of the short-term fuel trim value and long-term fuel trim value is within (+) 35 % (engine coolant temperature is more than 75 °C (167 °F)), the system is functioning normally.

MONITOR DESCRIPTION

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Monitor Strategy
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Typical Enabling Conditions
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Typical Malfunction Thresholds
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Under closed-loop fuel control, fuel injection amount that deviates from the ECM's estimated fuel amount will cause a change in the long-term fuel trim compensation value. This long-term fuel trim is adjusted when there are persistent deviations in the short-term fuel trim values. And the deviation from the simulated fuel injection amount by the ECM affects a smoothed fuel trim learning value. The smoothed fuel trim learning value is the combination of smoothed short-term fuel trim (fuel feedback compensation value) and smoothed long-term fuel trim (learning value of the air-fuel ratio). When the smoothed fuel trim learning value exceeds the DTC threshold, the ECM interprets this as a fault in the fuel system and sets a DTC.

Example:
The smoothed fuel trim leaning value is more than +35% or less than -35%. The ECM interprets this as a failure in the fuel system.