O2 sensor code and running rich
 

i just purchesed a 1996 volvo 850 glt
the check engin light came on and read code and it was p0141 rear o2 sensor heater.
replaced sensor and 3 days later the light came back andhad the code p0172 system running too rich (bank 1) that code showed up twice .... wondering what might be going on and any advise

thanks every one you are always such great help

Hope this two links help
http://www.obd-codes.com/p0172
http://www.obd-codes.com/p0141

Well, I just got my car back from days of trying to figure out that same code. I ended up doing a full tune up, replacing my front O2 and my FPR. Still had the code. PO172 99% of the time is a vacuum leak somewhere. Most commonly it is the elbow under the power steering reservoir. I had that happen a year ago. So, have your car smoke tested at a shop. Mine charged me 25 to do it. Yours might be more since my shop is 100% awesome.

My problem (the reason for that code) is the connector at the computer became slightly corroded and was giving a wrong reading to the computer. Basically the rear O2 looked like it was bad at the computer reading through the OBD2. But if you tested it at the connector with a diagnostic computer it would read fine. After 8 hours of diagnostics today and testing lots of different parts on the car this is what they found. My car is awesome now.

Do you have a loss of power? Is it NA or turbo? Has your MPG decreased at all since? I feel I am a master at this code since it has been two weeks of solid diagnosing and changing parts and brain storming with my mechanic about it. So, if you have any questions let me know.

Good luck,

Where is the elbow under the power steering reservoir? What does it look like?
Is it on the drivers side or somewhere else on a Volvo 850GLT?

small rubber line coming from the passenger side of the intake manifold. tight fit but if you remove the upper radiator hose from the housing you can get your hand in there a little easier

It is the primary measurement device for the fuel control computer in your car to know if the engine is too rich or too lean. The O2 sensor is active anytime it is hot enough, but the computer only uses this information in the closed loop mode. Closed loop is the operating mode where all engine control sensors including the Oxygen sensor are used to get best fuel economy, lowest emissions, and good power.
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Lavender Oil Torrance Med Spa

Thanks. It seems that your reply
is about five years old, so I don't know whether you will receive this message or not. I bought a 2005 S80 today which has a problem. After cranking it and letting it run a few minutes, it began blowing out lots of white smoke from the exhaust. This was within the first half mile of driving. In less than one mile, the car lost power and had heaps of white smoke behind me. Does anyone have any instant guesses as to what I should be looking for and what I'm likely to find as my trouble shooting begins? Thanks for any help.