96 monte bad injectors?

I have been reading some of the other posts and it seems that i am having the same problems that others are having with theres!

i recently changed and injector in the number 2 cylinder and it started to run good and then i have a number 3 missfire. so it probly is a good time to go ahead and replace all of the injectors huh? any ideas on places to get injectors cause around here they are not cheap!

also i have what seems to be a stuck valve in the 2nd bank there is a wired click that comes from that area it comes and goes. if i drive it for a few minutes its fine. anyone have any ideas?
it sounds as though there is a piece of metal in the engine right by the cams. i have no idea! major concern for this one!

I had 4 fuel injectors replaced on my 1999 Monte--3 replaced at 10,000 miles, and another at 11,000 miles.

The guy at the dealer said it was because of bad gas. I didn't believe it then, and after reading this message board, I certainly don't believe it is anything other than faulty parts.