Any codes or messages on instrument panel?

Aha!
pretty loud clunk for a test but that explains why it only happens on initial start-up.
Thanks for sharing.

This should help.

Exhaust system to turbocharger bolts: Torque to 24 Nm

Cylinder head: Tighten the screws in sequence from the center and outwards.
Stage 1: Torque to 20 Nm
Stage 2: Torque to 60 Nm
Stage 3: Tighten/rotate 130°

Manifold bolts – cylinder head side: Torque to 25 Nm

Pipe screw ...

With the 2004 S60 i've always had this issue but did not make much of it, but notice the same issue on a 2002 S60 i recently purchased for my daughter.
When I go to start driving (and only on initial startup) when I turn and get a few feet (20 or so) I hear a "clunk" coming from the front of the ...

No codes are coming up on the scanner. I'll check the temp sensor tomorrow (just got done replacing the front wheel bearing). I know another little quirk is when the car is in park and you rev the engine up to 2k and let off on the gas...the car will stumble a little when the needle drops down to ...

i never replaced the Converter. On that car i used a spark plug fouler to move the sensor back from stream.
So far (after about 2K miles) no more CEL.

So you basically inserted a LPF - low pass filter - in second O2 circuit and ECU now reads the slower integrated signal, good to know.
YES sir!!
There is nothing wrong with the O2 Sensor (computer not happy with reported Voltage/Frequency)
I used the resistor to drop signal voltage from 0.9V to 0 ...

I always thought it was the 2003 and 2004 that had the fandangled oil trap. Also I wasn't aware it was in any way connected to intake vacuum.

Great work draser and to you quietcoolone for persistence in this matter.
There is a small elbow hose from intake to oil trap-- (a real pain fitting onto ...

Informative thread!

ECM 4801 has returned on our 2001 V70XC, three weeks after replacing both HO2.

VIDA DTC shows...
Yellow Dot - ECM 4801 - Two Way Catalytic Converter (TWC), incomplete performance check.

The fault tracing points to four possible Intake and exhaust vacuum leaks, and 5th is TWC ...

If you have been following this thread, you know i had already "cleaned" the oil trap box and hoses. Unfortunately that was not enough because the oil trap has a regulator inside that can't be cleaned. I cut it open for you to see what i found inside. This section of the trap connects to the intake ...