general problems of the 2003 GMC C2500

While driving, large amount of smoke came out. Took it to gm dealer who said that it the fuel injectors were leaking. Looked online and noticed hundreds of reports of the same action. GMC apparently did an extended warranty for the issue, but only covered it for 7 years from time of purchase and up to 200,000 miles. Talked to local dealer who denied the service and gm wont replace the fuel injectors.

I keep getting reduced engine power p1516 code . Reading the post's on the internet this is a real common problem. Also the speedometer will display 120 mph sitting at a traffic light.