Ecu
 

I am installing an air/fuel ratio gauge right now on my 1987 190e 2.3-16V and am having trouble finding the o2 sensor wire. I see that the o2 sensor wire goes into the passenger side floor from the exhaust but i am having a pain trying to find out where it comes through to the engine compartment!! If it does at all... If someone knows where the ECU on this car is it would be a big help!! Thanks!

Uhh... why do you want to tap the wire at the ECU? What's wrong with the same wire closer to the sensor?

Sixto
95 S420
87 300SDL

only to find wire
 

i just want to trace where the wire to the o2 sensor is then i will hook up closer to the sensor..