Remembering why I
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AO Silver Member
Join Date: Sep 2001
Re: Simple way to check the Lambada probe..?
A good check of the lambda can be done with a cheap digital voltmeter as it says on that link. With the car warm and idling, connect the DVM to the output wires of the probe (with everything plugged up). You should see around 0.5v (it'll actually be switching quickly from near 0 to near 1). Blip the throttle and it should jump about dramatically and rapidly for a couple of seconds before settling down again. If it doesn't react instantly (or at all) to the blip then either the probe itself is FUBAR or, my old favourite, the heater isn't working. This test was how I finally caught my car playing up and found the dreaded heater fuse fault.
The heater itself can be tested by measuring the resitance (3 or 4 ohms typically) but the signal output is high impedance so needs the DVM to measure, and only when the probe is up to temp.