02 fuel injectors

[qinlet]

After a few battles with the dealer I finally got all8 injectors changed and everything ran great until about 2 months later i noticed the fuel mileage was starting to drop off and I could see some black smoke again, does that mean I got a bad batch of new injectors and will have to go through all the battles with the dealer again to get new ones? I was hoping the new injectors would be the end of my problems. Any ideas?

[More Power]

There are several possibilities for your current situation.... i.e. dirty air filter, fuel filter, dirty MAF sensor, softer tires, fuel quality or changes in driving habits.

[Rabbler]

If it is bad injectors I believe GM gives you a 1 year warranty on replacement parts.