2007 Porsche Cayman S: P0159 (O2B2S2 low signal)

[boogieman065]

I'm baffled trying to chase down this code.

P0159: Oxygen sensor modulating slowly.

So far, I've changed my air oil separator (known Cayman issue to cause fouled sensors), O2 sensor, and even tried to use an O2 sensor spacer to see if I'd get a different result. The code just keeps coming back.

O2B1S2 consistent reads between .6-9v

O2B2S2 consistent reads similarly, but I noticed it'll dip to .3v for just a second.

My hypothesis is that it's not the cat (spacer would've caused a different reading?) and it's not the O2 sensor (replaced, visually looks great when I added the spacer today).

What would cause the B2S2 to drop to .3v though? Sick of this code and having to erase it. Car has 136k miles.

[Jeff Alton]

Confirm you replaced the secondary sensor (post cat) On Bank 2? That is driver's side on your Cayman S.

Cheers

[jlong]

If you changed the AOS, did you also remove all of the intake tubing to clean up the oil left in the intake tract? You might be surprised as to how much oil can remain in the intake to refoul new sensors.

[boogieman065]

Originally Posted by Jeff Alton

Confirm you replaced the secondary sensor (post cat) On Bank 2? That is driver's side on your Cayman S.

Cheers

Oh....my....fk....Gawd. I'm used to conventional cars and have been messing around with the passenger side. Lol.

Originally Posted by jlong

If you changed the AOS, did you also remove all of the intake tubing to clean up the oil left in the intake tract? You might be surprised as to how much oil can remain in the intake to refoul new sensors.

I changed the tubing as well. Thank you!