dustrat

I own a 2004 impala 3.4L. So the other day on my way to work my car stalled at a stop light and room a few cranks to fire up and after it did it ran rough until I got up to higher speeds. Then a few miles down the road it died again and took more cranks to fire it up and i realized I bad to kinda hold the pedal down while I came to a stop to keep it from stalliong. Later on that day checked and engine light finally came on so hooked up and read one code po172 basically running rich code. So k bought new air filter and maf cleaner and cleaned maf sensor. Problem still there on my way home and seemed to start misfireng and getting worse. Also check engine light was solid then began to flash by the time i got back to my towns auto zone I plugged in and had 5 more additional codes. Po132 po401 po520 p1811 and po300. Oh and also as I said the first code po172. As I try to leave auto zone car won't start at all like its not firing I'm guessing the plugs may have fouled out due to the initial po172 code causing a chain of new codes. I guess first I should try and change plugs and see if i can fire it up to trouble shoot the initial code po172. Any suggestions? Do you think the po172 code triggered the rest of these codes on my drive home and any suggestions as to what might be causing this.