Greetings fellow 850er's, I've been getting two strange computer codes that pop up every couple of days. A P0440 (emission control system failure), and a P0136 (sensor circuit malfunction, bank 1, sensor 2). I've got no other apparent symptoms.

Is there any way to get a sense of what or where that bank 1 sensor 2 is or what the failure may mean?

Sounds like a vacuum leak to me. Check the hoses from the vacuum cannister to the intake manifold for cracks and soft spots. Also the check valve in the vacuum line.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

That is your rear 02 sensor, I think. Please note, it may not be the sensor itself. Other people here can tell you what may be causing that code to be thrown.

Bank one sensor two is the rear O2 sensor. It's primary function is to monitor the catatlytic converter efficiency.

When I look up your P0440 I get evaporative emissions control system malfunction. Could be as simple as a loose/worn out gas cap or something more costly like a faulty purge valve or bad canister.

Mark

Well, on the recommendation of Klaus, I went through all the vacuum elbows, replaced a few iffy ones, and reset the code. The light came back on, but only after about an hour of driving. Now, every time I reset the light with that code it takes about that long to come back.

Mark, I was hoping to get more details about the purge valve and canister you mentioned. What exactly do those do, and where are they located?

I hesitant to start blindly replacing rear O2 sensors given their expense. Any other ideas as to the trouble-shooting route I could take? Thanks!