02 Buick Rendezvous chugging stalling no check engine light?

The truck has been chugging and stalling for about a month now. Had check egine light on got codes said maf sensor, changed myself same problem and still check engine light, took to dealer when I did have check engine light on said bad catalytic converter got replaced at another shop as the dealer wanted 1200 ! Did not fix problem at all still same chugging and hesitating! Had dealer check again since was misdiagnoses they replaced connecter on mafs free still same problem. After towing from dealer to house I drove it around with the problem light came on agian had it checked, Egr! I replaced it and fuel filter samething still. So this is where I am the chugging is constant when driving but if you just about floor it goes fine until she tries to idle this is when it will chugg and sometimes stall out. If it stalls out it can take a couple trys to get her started again. Once started sometimes will act up right away and sometimes after a couple minutes of driving. Not sure what it can be now no check engine light on for the last couple of days im lost not sure what it can be! Check engine light works I see it flash when I turn the key! Help!? !