The Air Fuel Ratio AF sensor has an output delay of a few seconds and the Heated Oxygen HO sensor has a maximum output delay of approximately seconds

Case

A/F Sensor (Sensor 1) Output Voltage

HO2 Sensor (Sensor 2) Output Voltage

Main Suspected Trouble Areas

1

Injection volume +25 % -12.5 %

,_TLT

Injection volume +25 % -12.5 %

♦ _TLT

-

Output voltage More than 3.35 V Less than 3.0 V

-LJ-I2

Output voltage More than 0.55 V Less than 0.4 V

2

Injection volume +25 % -12.5 %

♦ _TLT

Injection volume +25 % -12.5 %

♦ _TLT

• A/F sensor circuit

Output voltage Almost no reaction

-NG

Output voltage More than 0.55 V Less than 0.4 V

_nu5

3

Injection volume +25 % -12.5 %

t_ru~

Injection volume +25 % -12.5 %

♦ _TLT

• HO2 sensor heater

• HO2 sensor circuit

Output voltage More than 3.35 V Less than 3.0 V

-LJ-I2

Output voltage Almost no reaction

-NG

4

Injection volume +25 % -12.5 %

,_TLT

Injection volume +25 % -12.5 %

• Fuel pressure

• Gas leakage from exhaust system

(Air-fuel ratio extremely lean or rich)

Output voltage Almost no reaction

-NG

Output voltage Almost no reaction

-NG

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