legacycentral bbs

Well as some of you may remember i was having some idle issues, i was getting a code for the knock sensor and once when i first got the car it had a code for knock sensor and iac valve, i installed a brand new knock sensor and it seems to have gotten rid of most of my crappy performance issues, although i still suspect that the iac is an issue, has anyone had any luck cleaning the iac valve, today i poured about 2oz of seafoam down the big tube that goes to the valve and that didn't seem to help, out of curiosity i unhooked the tube that goes from iac back to the resonator box on the intake and my hesitation problem all but stopped, all rpm's the car pulled harder and felt less like it had problems,that leads me to believe that the iac is stuck or clogged w/crap. also my mechanic did a compression test and said the cyl next to the turbo was way off from the other cylinders, two on driver side were around 160 and the other 2 ranged from about 140 to 120, is this normal? i dont have any smoke, and it only has about 143 on the clock. thanks damon