car has 201,xxx miles 2006 m6 pacesetter lt, catlesss mids, SLP predator tune.vararam intake. bout a week ago car got p0171 and p0174 codes, car didnt act different in anyway still drove good, no loss of power. went camping for 3 days. got to my friends has and started driving home. car started running super rich i ended up getting 10.5mpgs got home, replaced MAF, cleaned tb, checked for vaccum leaks, intake leaks, cleaned spark plugs and regapped. threw in stock tune. problem still persists. oxygen sensors are about 10k miles old. during a warm start. car will idle perfect for ~30seconds and slowly start running more and more rich until it idles at 2.9gal/hour. if i rev and hold at any rpm ex- 1500rpm will stutter and drop to about 1200rpms. any thoughts or solutions would be great.