One problem related to fuel injector has been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
The vehicle was purchased in sept 2004. In March 2005 I started noticing it was hard to start in the morning when it was cold and it idled roughly and would stall when I pressed the gas pedal to accelerate. The dealer found nothing wrong with it then. In April 2005, with 9400 miles on it, the service engine light came on so I took it back to dealership. They cleaned out (flushed) the fuel system and proceeded to tell me not to buy "cheap gas" because sometimes it will have particles in it that can clog up the fuel system (then what is the fuel filter for?). Since then I have had the fuel system flushed three more times. I probably could have had it done more times, but it is extremely inconvenient to keep going to the dealership and being without a vehicle, so I just dealt with the rough idle and hesitations. I buy gas the same places as everyone else in my family, yet I am the only one experiencing this problem. I bought fuel injector cleaner and put it in the gas tank every couple of fillups. The dealership has offered to replace the fuel injector that keeps clogging, but of course none of the mechanics ever made note of which one it was. So when the problem recurs I must take it back to the dealership again.