[SoCal LS-L]

The same guy I always go to does a pretest for me, just to see what my readings are before we dive into the actual emissions test. On idle, my HC and CO2 shot thru the roof, but on the rev test they were pretty low, well within passing range. My car has new O2's and plugs, and I ran the "guaranteed to pass" fuel injection cleaner thru a tank prior. The car idles just above the mark that resides a smidgen above the zero mark, I guess from what Ive heard this is the correct idle speed?

So why is my car having so much trouble burning the A/F mix properly at idle??

(BTW, I cheated by using the small allen head screw partially hidden above the throttle linkage to keep the idle at 1100. Passed no problem.)

Could this be a clear sign my IAC valve is clogged or not opening fully?