Small misfire only when cold start

[Jon Blaze]

06 trailblazer 4.2 LT 59000 miles owned since new. Have had this problem for about a year or so. I cleaned the tb. about 4000 miles ago no better.

Cold start and there is a rough idle from the tail pipe. Hooked up a scanner and watched the misfire 3 and 5 went from 0 to a 2 for both of them stayed there for a few seconds then went to 0. Warmed up and now it stay at 0. Shut off and restart when it is warm stays at 0. I used a snap on solus pro to check it. No codes or check engine lights on. Just rough idle at cold starts. The weather doesnt change it.

 

[bigjerel]

You ever figure out the issue? Mine does pretty much the same thing every day whether the weather is cold or not. Runs rough until the engine warms up, then runs smooth as silk after that. I've swapped a bunch of parts out (plugs, cleaned TB, fuel pump/filter in tank, new PCM with tune from PCM of NC, new variable valve timing solenoid, new thermostat) but still chasing it around. Pain in the butt since it only does it when the engine is cold and hard to justify spending too much of my free time on it.