Help! My check engine light came on (11,000 miles past warranty), mechanic said the code was P2716. Also noticed it was shifting hard sometimes. The local tranny guy was going to work on it, but said he couldn't get info from GM to do repairs; said it was OK to drive for awhile. Took it to the dealer, who couldn't work on it for several days, also said OK to drive. Did the job for $750, then told me the trans. has bigger problems and there were metal bits & copper color in the pan. Should I have to pay for what they did, on top of whatever else it needs? Does it sound like my transmission is toast? I'm tempted to drive or tow it elsewhere, but we're in a small town 100 miles from the next nearest dealer. Any advice would be greatly appreciated.