Rough Idle on 2004 Impala SS

What is your question?

The rough idle only seems to occur after the engine gets warm "enough". The sputtering then starts and the current resolution is to let it sit and cool down. 131k and the manifold gaskets have been done. MAF sensor replaced a number of times over the years, but seems different as in the past, the MAF would just cut the car off and unplugging it would alleviate the issue till I could fix it. This started out as a engine revving problem with what seemed like "half" fires when trying to make the engine rev when it couldn't/wouldn't and the various repairs attempted so far include the ignition recall, some oil leak recall, new resonator (needed because the old one went and a catalytic converter replaced because Meineke said the CC's innards had "turned/flipped"? THe car will run great with seemingly more oomph, but when it's about 15-20 mins into a drive it acts up. Continually getting tougher and tougher to keep idling until it indicates it's done and won't start.

How long has your 2004 Chevrolet Impala had this problem?

few weeks