Ok, my 1995 Jimmy has had this intermittent code. I know its an emissions only code and does throw the car into limp mode. And I tried a new sensora while back and the code came back.

So, I am thinking wiring.

I really do not care about this CEL .... but now I am trying to sell it so I need to fix it .

Any idea where this rear downstream sensor's wires end up in the ECU? I would love to just run a new harness from the ECU to the sensor.

Is the ECU under the hood? Does anybody have pin outs for the ECU so I could just run new wires?

Thanks for any help!

James

 

Are you sure it's a code P0147. I don't see a code P0147. I can find a code P0141 that is a heated O2 sensor code.

You say you tried a new sensor wire....for what sensor?

 

Same code this dude got...

https://blazerforum.com/m_83626/tm.htm

Maybe I should just try swapping sensors...seems much easier than running new wires.

James

 

I don't know why you would run new wires. It sounds like an O2 sensor failure.
I also don't know what year truck the other post refers to. I was looking at codes for a '95

 

Your '95 must be a late '95 to have codes like this. If it is, you may have 3 O2 sensors total. One directly behind the 'Y' in the y-pipe (B1S1), one directly ahead of the catalytic converter (B1S2), and one directly behind the catalytic converter (B1S3). If you have 3 total, then you can try swapping B1S2 to B1S3.

But if you have already replaced the B1S3 sensor, it may be wiring or the ECU itself. How long ago did you replace it and with what brand sensor? Did the new sensor cure the problem initially? If it did, then it could just be that the sensor was lazy from the start...