Xemodex ETM and Idle Problem

[VolvoS80Joe]

2001 Volvo S80 T6 with 262,000 Miles
Xemodex ETM replacement at 200,000 Miles
Car now exhibits erratic idle at times and will buck and stall. Other times it functions properly.
No engine codes with code reader. Obviously no MIL on.
When RPM's are above 1,500 everything seems OK. Power seems Ok.
Added gas drier and replaced fuel filter since problem started almost immediately after fill up.
Three tanks of gas later and problem still exists.

Could ETM be dirty and binding?
Could it be something else?

Any opinions or help is appreciated.

-VolvoS80Joe

[VolvoS80Joe]

Update:

(1) No reply from Xemodex concerning email I sent. Not good.

(2) No reply from 42+ reads. I understand. I didn't have an answer either, hence the post.

(3) New code reader found P1238 - Turbo Control Valve. Replaced in 5 minutes once engine was cool. 1 electrical connector and three vacuum hoses. Genuine Volvo part was $79.00 at local parts store. Cheaper online but I didn't want to wait. We will see if this fixes the problem. I cleared the fault and it stayed clear until the surge / stall action started again. Code was re-read and was P1238 again.

(4) So I heartily recommend the $99.00 Autel Code Reader. Live data. I see that my Bank 3 O2 sensor is weak. I love the MAF Sensor flow signal and the Throttle Position signal. You can record too. Way better than my older scanner that cost more.

I will update in a week or so to confirm the TCV was the problem.

-VolvoS80Joe