Vectra o2 sensor

After lots of OBD faults reported, getting to the bottom of them there is just one remaining possible issue...

1.8 2003 C petrol SRi. Its constantly reporting the O2 bank 1, sensor 1 heater as a pending code, but the MIL doesn't light and the code is not stored. There is only one bank - one front and one rear. This is the front one below the manifold. Is it normal for the fault to show please?

I didn't think the heater was needed for the front O2 sensor, only the rear which takes longer to warm up.

Reply to
Harry Bloomfield
Loading thread data ...

Functioning heaters for both o2 sensors are expected.

Tim.

Reply to
Tim..

Tim.. wrote on 04/01/2014 :

He has just had another fault show up from a cool start - a fuel trim fault. Might that be attributable to the lack of the O2 heater?

The sensor was replaced yesterday by the garage, so I guess it goes back to the garage to see why its not working, thanks.

Reply to
Harry Bloomfield

I had a similar problem on a Toyota, I rewired the heater circuit through a suitable large resistor and the problem went away. AFAICS the heater circuit improves emissions by a tiny bit in the first few minutes of running. The ecu expects to see an appropriate voltage drop on the heater circuit and flags a fault code if the drop is not found.

Reply to
Mrcheerful

fuel trim faults are often caused by inlet or exhaust leaks and sometimes by a dodgy maf sensor.

Reply to
Mrcheerful

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.