Faulty Signal

Checking Compression
- Carry out a compression test.
- Is compression OK?

If reading is OK:
^ Proceed to test step below.

If reading is incorrect:
^ Remedy as necessary.
^ Then Proceed to Verification section below.





Checking For Air Leakage In The Intake System
- Check for air leakage.
- Is there any air leakage?

No:
^ Proceed to test step below.

Yes:
^ Remedy as necessary.
^ Then Proceed to Verification section below.





Checking For Air Leakage In The Exhaust System
- Check for air leakage.
- Is there any air leakage?

No:
^ Proceed to test step below.

Yes:
^ Remedy as necessary.
^ Then Proceed to Verification section below.





Checking Fuel And Residual Pressure
- Check fuel and residual pressure.
- Is pressure OK?

Yes:
^ Try a new three-way catalytic converter (TWC).
^ Then Proceed to Verification section below.

No:
^ Remedy as necessary.
^ Then Proceed to Verification section below.





Verification
- After carrying out the repair, check that the fault has been remedied as follows.
- Ignition off.
- Heated oxygen sensor (HO2S) connected.
- Go into diagnostic test menu.
- Test drive car.
- Watch EFI-443, wait until the status of EFI-443 goes over to tested.
- Read diagnostic trouble codes (DTCs).
- If EFI-443 is stored it should have the status intermittent fault.

If reading is OK:
^ Fault corrected

If reading is incorrect:
^ Proceed to test step below.

Fault-tracing Information
- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?

Yes:
^ Fault not corrected

No:
^ Return to Checking Compression section above.