O2 sensor or something else

[HRDWRK]

Hi:
I have been getting codes OF 04, 14 and 17 which I believe they are all related to Bank 2 second O2 Sensor. First, my understanding is the seond O2 sensor is the last O2 sensor toward the end of the car. It is a little confusing because it read the second O2 sensor is the one after the cat, which on these cars cat is right below the exhaust manifold, but this second O2 sensor is after what looks like a resonator. I am mistaking the cat and resonators? Are there 3 O2 sensors?
Anyways, if I am not making a mistake, I had a used O2 sensor which I thought it is good and I repalced it with it. The same codes again. I then swap the Bnak one (passenger side) with Bank 2 (driver) side sensor and I still get the same codes for Bank 2! So, my assumption is the O2 sensors are okay.
Worth mentioning that on two occasions I also got the code OF22 which I belive is camshaft Vanos control.
These coded just don't pop up every time I start the car. They usually happen after the engine is warm or I have been drving for a while. Specifically, Ihave noticed they come up often after I drive for a while, i turn the engine off and then when I start the engine after few minutes, like when I stop at groceary or something.
Any ideas?
Thanks

[edjack]

You have a pre-cat sensor, which on your MY, is in the exh manifold, ahead of the manifold-mounted cat. It provides an input signal to the DME to control the air/fuel mix.

The post-cat sensor, downstream from the second cat, is used to monitor the cat efficiency.

[Chedley]

You have a bad after-cat (rear) O2 sensor , and a bad camshaft position (cps) sensor on Bank 2.
Replace them with oem sensors, not the cheap after-market.

[HRDWRK]

So, I ended up changing the after cat O2 sensors with Bosh. I am still getting the same codes!!! Does it take a while for the system to stop throwing codes?! I h ave erased them twice so far but unfortunately them come back. The interesting id they don't come back right away after we start the engine after I have cleared the code. I have noticed it comes back when the engine has been warmed (driven) for a while and when I turn the engine off and restart it again. Like a short grocery shopping stop. I don't know if this mean anything.
The Vanos camshaft has not returned since I replaced the Vanos sensor.

[Chedley]

Can you be specific : Did you replace both after-cat O2 sensors (left bank and right bank) ? which codes come back ??

[HRDWRK]

I am getting PO161 on OBII and FO 4, 14 on ther round one (my mind has gone blank and I don't rememebr the name of the scanner!). They are all related to Bank 2, sensor 2.

[Chedley]

These codes indicate a bad after-cat O2 sensor on Bank 2.
Did you install a new sensor ? Did you check its electric connections ??

[HRDWRK]

Yes,
I changed both side after cat O2 sensors with brand new Bosh O2 sensors. Visually the connections and their lines are good.

[HRDWRK]

At this point I think I have a bad wiring somewhere. The only things is the wires are so burried under insolations and so many covers that it is very hard to trace them :(

[HRDWRK]

662986662987
Okay, it is fixed. The O2 cable was jumped out of the clip and it was rubbing against the driveshaft! Crazy!

[Bmwe39528i1998]

Good find:)

[Chedley]

Good job.
I'll pay attention to it next time I change my O2 sensors.