My issues with my 2000 S40 continue. I'm not out of the woods just yet!

Last week I replaced the FPR and IAC valve after the car wouldn't start without a foot on the gas pedal. It starts just like new now and has even eliminated my issue of a 8 to 10 second crank time.

However, despite the fix, I immediately got a new CEL code and now, a week later, a very low, rough, jumpy idle tonight. The code I pulled is P0113 - OBD-II Trouble Code: P0113 Intake Air Temperature Circuit High Input. This code has been there for a week and was present even without the issue of my low idle and stalling.

Anyway, the idle sat at about 200-300 rpm when stopped tonight, both in park and at red lights. If left alone it would periodically move up, step by step, to about 700, and then back down again after coming to another stop. Stalled out in the lot of the supermarket when I was backing out of my spot.

I have been searching for about an hour and figured that tomorrow I'll clean the the throttle body and see if maybe it helps. I also found that the MAP sensor can cause similar issues. I'll try cleaning that as well.
Anyone have any bright ideas? I checked all my hoses (or tried to) last week before buying new parts, and didn't notice anything. I can always look more.

Thanks in advance.

 

IAT sensor on top of the intercooler.

 

Cleaned the MAF sensor, MAP sensor, and TB this morning with the according sprays. No luck with the low erratic idle problem.

Migbro, thanks for the suggestion. That sensor looks like it might be the cause of my CEL and a mechanic told me it might be the cause of my idling problem, but the evidence online about symptoms of a IAT sensor and my common sense make me think otherwise...

Now to figure out what to do next...

 

Wut? So you're saying the code and the mechanic are wrong. Because your common sense says so. Or do I misunderstand your point?

 

Well, the OBD website I linked to in the first post said there are no symptoms usually aside from a CEL.
A page on the ehow website here: Symptoms of a Bad IAT Sensor | eHow.com says nothing about a low rough idle.
My car has had a rough idle for about a year now and the CEL only came on last week. It's not something that started all of a sudden when the light came on. Plus, the light was on for a week before I started having trouble with the low idle. I drove over 200 miles. Wouldn't the symptoms show up sooner?

The mechanic didn't really hear the full extent of my issue, just that my idle was low. So maybe he could've given a false assessment over the phone. So yes, my common sense here is saying there's something else, like a possible vacuum leak, that has been developing over time without me seeing it.