Hi all,

From what I read in this forum the voltage on the output of the O2 sensor is supposed to be around 450 mV (fluctuating a bit) . I get only about 30 mV on both the 260E and 300E. Revving the engine decreases it to about 10 mV .

The way I measure it is that , while the engine is idling at operating temperature, I place one terminal of the digital voltmeter on Battery's negative Pole and the other terminal at the wire coming out of the O2 sensor. The voltage at the flat connector, the heater, is about 13 V. Interestingly, the voltage at the ECU pin where the O2 sensor is supposed to be connected is 450mV fixed.

I must be measuring it wrong since the cars are running fine: hovering around %50 duty cycle , EHA current normal, etc. I replaced the O2 sensors few weeks ago.

Any input will be appriciated.

Thanks.

__________________
Zorin

'88 Benz 420 SEL
'79 Porsche 911SC ('87 Carrera Engine)
'00 BMW 540 Sports Package
'99 Land Rover Discovery

86 300E - Manual (sold)
88 260E (sold)
84 944 (sold)