My '03 S40 just recently starting stalling. It happens only at idle. I have cleaned the MAF and the ICV, but engine still stalling. I tested the ICV on my workbench with 12v and it appears to operate. When I drive the car it seems to have less power than I remember. It is my daughter's daily driver so I can't say for sure about the power. It is throwing catalytic converter codes but it has been doing that for years. Is there any other testing I can do on the ICV? Any ideas would be appreciated.. Thanks in advance.

 

Faulty fuel pressure regulator, maybe? Is it throwing any codes? Have you tried replacing your fuel filter? Did you clean the throttle body as well?

 

Replaced fuel pressure regulator last year, just replaced fuel filter. I still suspect ICV but not sure how to test it.

 

Try cleaning your throttle body too. Easy job.