Hi guys, can anyone answer me a question?

My car, a 1992 Vauxhall Senator 3.0 12v, came with a printout from a garage who had serviced it saying Lambda sensor 'not switching.' Is the only cure a new sensor? The performance seems OK but the economy is pretty bad and the ecu light comes on occassionally.

Any help would be appreciated...

Cheers

Brian

 

I don't know about the Senator, but on my Dad's Vectra we could put the ECU into display mode and the engine light would flash the error code.

His was showing oxygen AND MAF sensor. Turned out to be a bad MAF.

If the sensor is faulty, then yes the only cure is a new one. It'll run very rich without it working properly and you'll (possibly) fail a roadside emmisions test and/or MOT.

Stefan

 

All lambda sensors degrade with time. This will eventually lead to incorrect fuelling, usually running rich and increasing fuel consumption.

When the ECU is running closed loop (i.e. steady engine speeds), the lambda control is constantly varying the mixture about the optimal value. So it continually goes from slightly leaner than optimum to slightly richer than optimum to slightly leaner etc. If the lambda sensor is no longer able to determine when it crosses that threashold then it needs replacing.

The reason performance seems OK is that lambda control does not function under transient conditions such as when accelerating. It is then in open loop mode and uses map data to define the fuelling required.

In summary if it's not switching, it needs to be replaced. The reduction in fuel bills will offset the cost soon enough so don't think twice about getting it changed.

HTH

 

Thanks for that, it all becomes clear now

Brian

 

Hope This Helps

HTH!!

 

Oops I see!

 

NP

(think this thread has been muppetised!!!)