Erratic idle + erratic acceleration on a 2001 S40

[mrbrize]

Ok, someone from the ETM section confirmed there is no ETM on my S40 :

"Your S40 has an old fashioned cable connecting gas pedal to the throttle, there is no ETM in it.
Have the vehicle scanned and see what the codes are, my guess bad O2 or high fuel pressure."

Could someone confirm I will have codes, even though I don't have any lamp on on the dashboard?

And to come back to one of my previous question, what did the mechanic mean I saw mean by Throttle Housing? Is that the same than the throttle body?
The mechaninc said that even after cleaning it, a valve within doesn't seem to work properly. Could that be the cause of all the problems I described?

Sorry for all the questions - thing is, I am out of warranty, parts and labour are extremely expensive here in Ireland, and on top of that, I am not quite sure a regular mechanic would proactively investigate some parts unless specifically asked.

Cheers!