Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Component Inspection
- CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
- Turn ignition switch OFF.
- Disconnect air fuel ratio (A/F) sensor 1 harness connector.
- Check resistance between A/F sensor 1 terminals as per the following.
A/F sensor 1
Condition
Resistance
+
-
Terminal
3
4
Temperature
25 deg. C (77 deg. F)
1.80 - 2.44 Ohms
1
Not existed
2
4
1
2
Is the inspection result normal?
YES
INSPECTION END
NO
GO TO 2.
- REPLACE A/F SENSOR 1
Replace A/F sensor 1. Refer to Exploded View .
CAUTION:- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads.
INSPECTION END
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.