1st round in the emissions ring = FAIL, High CO, High HC, ok NOx.
replace O2 myself, take the car to a dealership w/ a corvette "specialist".

They diagnose a misfire in 2 cylinders, (which explains surging and stalling @ idles and stops).

They do a little tune up, Replace Plugs, wires, clean TB, clean fuel delivery system. I believe he also adjusted timing and TPS, not entirely sure. I checked timing and its less than 6* Before TDC.

My new problem:
Before I was worried about stalling. now the stalling doesnt happen. but I do get a very strong surge intermittently and a very rough banging or something. I hope its not detonation. What exactly happends when an engine is knocking? The "rough spot" feels like it happens once every cycle. It is worst when engine is under load and i feel as if im losing performance. Dealership reopens monday and heads will roll. Im paying so Much because I want **** done right guaranteed.

Any Ideas on what happenned? BTW the really rough condition didnt exist before, even though It misfired before, I never felt any uncormfortably rough sitiantions.

Thanks for the help