what happens if your lambda probe aint working

[gorgeee]

i've had all sorts done to my car but it still aint running right so just wondered if anyone knows the lambda's function and how it works

[Davenotouring]

What year is your car?

The lambda sensor is an oxygen sensor which sits in the exhaust near the engine.

Not many e30's were fitted with them as they are normally only fitted to cars with catalysts?

If you do have one and your car is running badly, it may be worth getting the emissions checked.

[gorgeee]

hi Dave its a 1991 J reg car
but then by the sounds of it i dont have 1 anyway

[Quaser]

If it's a j reg car, then it's almost certain to have one.

Me and my mate have it on a 325 and 320 engined motor - both on H Reg.

Apparently, the cat is built into the centre box!

Q

[jmc330i]

My car is a 1991 J reg 325i and does not have a Cat or Lambda sensor. The engines from '91 are 'Cat ready' but the Cat is not needed unless the car was first registered on or after 1st August '92.

[Danstable]

Mine is a 91 J reg and has a Lambda sensor.....and a cat as far as I' know.

[Davenotouring]

Can anyone who thinks they have a cat look under the bonnet for a sensor screwed into the manifold/downpipe...

I definately don't....

[Brianmoooore]

The connectorfor the lambda on an E30 is a round 4 pin plug clipped under the front battery tray.
Non cat E30s have a blank cap screwed on here, but if you have a plug fitted here , then you have a lambda sensor. Follow the wire to find it.
A working sensor should produce a AC voltage, centred on about 0.5V. The frequency of this signal should be a maximum of about 2 Hz. Any more and the sensor is dud. Faster is better.
A car with a dud sensor will revert to default settings in the ECU, and the fault won't be to obvious until MOT time.
One symtom you can sometimes notice, is a rythmic rise and fall of the idle revs over a second or so.

[gorgeee]

hi thanks for this
so at mot time my 325 was running too weak even with screw fully turned could this be the lambda sensor faulty?
and is it fitted to the centre section or the before that in between the manifold?