940 Non-turbo,

First, thank you Steve for explaining the O2 wire color code. They are very helpful but I would not venture to test voltage now because I do not know if my voltmeter is built for 10 megaohm impedence.

Anyway to all the gurus out there I am getting worried over the expensive repairs that i might face over the 2-1-2 Diagnostic code.

I keep getting the 2-1-2 code after changing the O2 twice, once with a used unit (but working) and only yesterday with brand new Volvo unit. The code came back only minutes after installing it.

I am at a lost now and getting worried that I may have to replace a ECU, the cost of which I could not afford, whether used or new.

Can all the volvo gurus out there give me some pointers on this, like what else to check?
Can you all give me directions on determining if the ECU is really faulty?
And can I just go on driving the car with the 2-1-2 code there?
I will be driving long distance like for some 900 km in half an hour, and i have no choice but to do it with the 2-1-2 code there.

Please help, I just paid for a new O2 for no apparent benefit and this is a very costly experience. So, please, please help.

Information: when the used unit was hooked on, I unplugged the sensor from the terminator that goes to ECU and test voltage: From the black wire of the sensor pigtail i got .2 to .4V. at the green wire connector from the ECU end terminator I got .5V. Current is coming out from the black or purple wire of the ECU end. (I tested it with a test light) That is all I've done.

Thank you all

BTW I received the 2-1-2 after my car came back from an accident repair. I had to replace the bonnet, a left fender and a couple of lamps. Perhaps this might be useful information. All these have drained my very financial resources dry.

Regards
Laozong