[Engine] Oxygen Sensor Wiring

[jpbelondon]

Hi
02 Multispace Forte MFNFU
P0135/P0141 fult codes and using a lot of fuel.
Sonsors and fuse replaced but errors return.
Upon investigation "mouse nest" found under the air filter.
No obvious wiring damage but suspicious.
Does anyone have a wiring diagram that covers this and some tips for tracing/resolving?
Cheers

[Gadgetman]

Does it have the Sagem ECU?

If so, there's schematics in Haynes 'Professional Techbook' 3558:
Engine Management and fuel injection systems
(EMS DATA Vol 1 - Alfa Romeo to Mazda )

There's 4 wires running to the sensor.
According to the book(and Sagem/Lucas SL96 ECU)
1 - To GND
2 - To Fuse F11, 15A rating.
3 - Pin 22 on ECU connector.
4 - Pin 4 on ECU connector.

On Magneti-Marelli MM 8P MPi DIS
1 - to GND
2 - to Fuse 3
3 - Pin 29 on ECU connector
4 - Pin 12 on ECU connector.
Additionally, 3 and 4 seems to be a shielded cable, and the shield is connected to 16 on ECU connector.

Bosch Motronic MP 5.2
1 - to GND
2 - to Fuse 11, 10A rating.
3 - Pin 28 on ECU connector
4 - Pin 10 on ECU connector.
Additionally, 3 and 4 seems to be a shielded cable, and the shield is connected to 14 on ECU connector and GND.