Change engine gasket and car no start
MERCEDES-BENZ 190 (W201)

Hi, do you where the oxygen sensor is located in my Mercedes benz 190e 1987 102962 2.0 118 hp 87 Kw. I changed my engine gasket and could not start the car. I discovered later that I had a fault flowmeter when it could not be adjusted for rich and pour fuel. After I thought I had replaced the non-working parts – I found that I could not start the car unless it was running lean. I also have no current test from EHA – I tested with 3 different EHA’s and all have no current coming out of it – but have input voltage 8.6 volts and also even correct resistance between connectors. But the is no current coming of the EHA. I am guessing that the ECU is not feeding back info to the EHA for it to work. No current meaning not even the baseline current requirements. If I could find the oxygen sensor I could change it out but can’t see any or don’t recognise any that could be. Could you help please? Thanks.